Being happy seeing the sun shine across the buildings is a relatively harmless, simple & beautiful pleasure however, according to Buddhism, it remains a 'sensual pleasure' that the mind depends on or takes refuge in for happiness.

Buddhism teaches about an even greater happiness or pleasure when the mind experiences the 'non-sensual pleasure' of meditation/concentration/jhana.

Therefore, as Dhammapada 209 states:

If by renouncing a lesser happiness one may realize a greater happiness, let the wise man renounce the lesser, having regard for the greater.

Benefits of “Mental Noting” during positive events?

From an insight meditational perspective the benefit would be to cultivate impartiality and objectivity towards both pleasant and unpleasant sense objects.

If one is cultivating impartiality towards unpleasant phenomena but partiality towards pleasant phenomena, then one cannot really be free from attachment and ultimately suffering.

Ven. Yuttadhammo likens pleasant phenomena to sweet poison, i.e. the stuff people give to ants in order to exterminate them. The poison is sweet smelling so the ants bring it down to their nest, thereby poisoning all the other members too.

Pleasant sense objects is like this since they are conditioned meaning they are subject to constant change and flux. One cannot be free from addiction if endulging in either pleasant or unpleasant phenomena.

"..has allowed me to disassociate myself with any such passing clouds..", sounds like annatta-sanna (perception of non-self) to me. I dont think there is anything wrong with it. As a matter of fact, Buddha encouraged us to stay in that perception. and if focusing on "passing clouds" that might even be an impermanent perception (annicca sanna). These two perceptions are leading straight to nirvana. I dont remember exact which to which, but Buddha compared perception of non-self as archer who can shoot far, and impermanent perception to sharp accurate shooter. Together makes a great archer who can destroy enemies.

Is there something I'm doing wrong or missing here?

According to the the original Buddhist teachings in the Suttas you should be aware of:

the latent tendency to lust reinforced by being attached to pleasant feelings

Pahāna Sutta

Also similar passages in: Cūla Vedalla Sutta, Mahā Vedalla Sutta, Samma Ditthi Sutta, Cha Chakka Sutta, Dhātu Vibhaṅga Sutta, Titth’ayatana Sutta, etc.

Where does the latent tendency of sensual lust lie latent?

The latent tendency of sensual lust lies latent here in the two feelings [pleasant and neutral] of the sense-sphere

Quote from Pm §587/123, Vbh §816/341, cf S 45.175 in Anusaya by Piya Tan

Cha Chakka Sutta goes to the extent that is is not possible if you delight in the pleasant.

...

Latent tendencies

LATENT TENDENCIES ARISING THROUGH THE EYE. Bhikshus, dependent on eye and forms, eye-consciousness arises.

When the three meet, there is contact. Dependent on contact, there is what is felt as pleasant, or as painful, or as neither pleasant nor painful.

When one is touched by a pleasant feeling, one delights in it, welcomes it, remains attached to it. Thus one’s latent tendency of lust (rāgânusaya) lies latent.

When one is touched by a painful feeling, one sorrows, grieves, laments, beats one’s breast and falls into confusion. Thus one’s latent tendency of aversion (paṭighânusaya) lies latent.

When one is touched by a feeling that is neither pleasant nor painful, one does not understand it as it really is, the arising, the passing away, the gratification, the danger, and the escape with regards to that feeling. Thus one’s latent tendency of ignorance (avijjā’nusaya) lies latent.

Bhikshus, that one could make an end of suffering here and now, without abandoning lust for pleasurable feelings, without removing aversion towards painful feelings, without uprooting ignorance towards feelings that are neither pleasant nor painful this is IMPOSSIBLE.

...

Abandoning the latent tendencies

ABANDONING LATENT TENDENCIES ARISING THROUGH THE EYE.

...

Bhikshus, that one could make an end of suffering here and now, having abandoned lust for pleasurable feelings, having removed aversion towards painful feelings, having uprooted ignorance towards feelings that are neither pleasant nor painful this is POSSIBLE.

...

Dhātu Vibhaṅga Sutta, Titth’ayatana Sutta establishers the 1st 3 Satipatthana should be done at the level of sensations and Chachakka Sutta establishes that the last Satipatthana is also at the level of sensations though it does not cover the full extend of Dhammanupassana.

So what ever pleasantness (and even neutral and unpleasant feelings) you experience be aware of:

• arising and passing nature
• keeping you mind firmly equanimous.

Anything else, you are doing it wrong.

Benefits of “Mental Noting” during positive events?

Any metal verbalisation creates Verbal Fabrications which you should explicitly avoid or your practice should be such that leads to ending of fabrication than creating them. Creating fabrication means future existence and misery hence hence there is little benefit though this might help develop a shallow form of Samadhi. See: Vedalla Suttas, Samma Ditthi Sutta.

Formations

Saying, “Good avuso,” the monks delighted and rejoiced in the venerable Sariputta’s words.

Then they asked him a further question: “But, avuso, might there be another way in which a noble disciple is one of right view, whose view is straight, attained to wise faith in the Dharma, and has arrived at this true teaching?”

“There might be, avuso.

When, avuso, a noble disciple

understands formations (sankhara),

understands the arising of formations,

understands the ending of formations, and

understands the way leading to the ending of formations,

in that way, avuso, he is one of right view , whose view is straight, attained to wise faith in the Dharma, and has arrived at this true teaching.

And what are formations, what is the arising of formations, what is the ending of formations,

what is the way leading to the ending of formations?

There are, avuso, these three kinds of formations:

the bodily formation,

the verbal formation,

the mental formation.

With the arising of ignorance, there is the arising of formations.

With the ending of ignorance, there is the ending of formations.

The way leading to the ending of formations is just this noble eightfold path, that is, right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, right concentration.

It seems that long-term noting will cause me to put a distance between pleasurable moments just as it would with negative ones?

This is because noting there is Vitarka & Vicara (also see: Vitakka,vicāra by Piya Tan) creating access concentration. Though this process is creating fabrication which is negative the Samadhi part is gives a positive result. The net result of the -ve and +ve aspect will change from mental state you are in when practicing and net result will be hard to quantify hence should be avoided. People who might have benefited from this may have practiced in such a way that there was a net positive result, but this might not always the case for everyone and the same person at different times.

Also see this answer.

I enjoy such emotions and whatever pain I experience from them being so fleeting is worth it. I'd rather maintain the duration by which I experience such moments, not shorten it with noting. I'm not sure what perspective to have in such cases and whether there is some greater benefit to continuing to do this for all situations?

Trying to shorten it is aversion and trying to prolong it is clinging which are extremes you want to avoid.

To get the best benefit follow Pahāna Sutta and other Suttas:

Bhikshus, there are these three kinds of feelings.

What are the three? Pleasant feeling, painful feeling, neutral feeling.

Bhikshus,

the latent tendency of lust should be abandoned in regard to pleasant feeling;

the latent tendency of aversion should be abandoned in regard to painful feeling;

the latent tendency of ignorance should be abandoned in regard to neutral feeling.

Bhikshus, when a monk

has abandoned the latent tendency of lust in regard to pleasant feeling;

has abandoned the latent tendency of aversion in regard to painful feeling;

has abandoned the latent tendency of ignorance in regard to neutral feeling—

then, bhikshus. he is called a monk without any latent tendency, one who sees rightly. He has cut off craving, undone the fetters,18 and fully penetrating conceit, he has made an end of suffering.”

Theory: if you don't acknowledge positive state, you are likely to become more attached to it and have suffering when it ceases (that's what the mind does automatically: liking → craving → (later) disappointment). You've known this for sure.

Practically speaking (but I am only guessing based on what you write) you should acknowledge/note very carefully:

• liking and disliking of conditions (of anxiety, negative thoughts, happy states etc);
• the intent to change a condition by noting - this might come after the previous (liking & disliking), if you don't note it. You seem to have the habit of avoiding unpleasant stuff by noting; so you avoid the condition by diverting your attention, replacing hatred by ignorance (both are roots of suffering; the third one is craving, as you know).
• the feelings of distance, disconnection, maybe sadness, isolation, loneliness etc. Disengagement has its price. (I am happy you could overcome your negative thoughts but maybe you need to overcome side-effects of that treatment now.)

Do not (ab)use noting to manipulate your experience, whatever it is, even if it is terrible: note the dislike, terrible, hate, anger, whatever it brings up. The goal is that you can fully experience negative, positive and neutral states, without making them go away or stay longer. Vipassana means "seeing clearly" - not "seeing clearly but only what I like" :)