Could you translate 'suchness' as "being perceptible to the senses"?

I think this would be an inappropriate translation. 'Suchness' is a quick way of saying "that which actually is, as it actually is", but not everything that 'actually is' is immediately perceptible to the senses. You'd have to begin with a Western empiricist assumption that everything which 'actually is' is ultimately accessible to the senses. I'm not certain that's a reasonable assumption...

In particular, the conditioned nature of karmic action — the metaphysical relationship between cause and effect — is not immediately perceptible. We can see the first (the 'cause'), and we can see the second (the 'effect') but the relationship between the 'first' and the 'second' has to be understood. It can't be seen in any simple, sensory manner, any more than we can directly 'see' the force of gravity.

'Suchness' certainly manifests as 'directly perceptible by the senses' because the mind is not discriminating or judging something. The mind is merely experiencing or perceiving, without judgment.

The word 'consciousness' ('vinnana') in Theravada Buddhism does not mean 'divided knowing', as it does in Hinduism. The Buddha used old terms such as 'vinnana' & 'namarupa' differently to the Brahmins (Hindus).

In Buddhism, consciousness merely means experiencing or knowing via the six senses. In Buddhism (MN 43), consciousness (experiencing) & perception (recognizing) are 'co-joined' and cannot function without each other.

Therefore, when the a Truth (such as the truth of impermanence or not-self) is directly recognized (perceived) and not judged as 'bad' or 'good' but merely merely recognized as 'just the way nature is', this is 'Suchness'.

I think things can be perceptible without consciousness, and that visibility is in some sense indivisible, so is perceived the same even when the visible thing is broken up.

In the oldest texts mn43, it says that what one perceives that one also feels & cognizes. That which is spoken of as perception can be explained as something cognized by that which is called mind, consciousness or intellect.

Creation, feeling, consciousness, perception are thought of as conjoined by Theravada.

Therefore the way you express it, i think would not be agreeable with the sutta expression.

It seems as you would separate consciousness from perception not by context but in a way that one can come before the other. If this is so then imho it is disagreeable in meaning as well as expression.

Consciousness is to be understood and intellect is to be developed.

The semantics of how you hold the doctrine in mind are very important to get right. If this doesn't occur then it is like a mistake in forming an algebraic equation. The term mind is to be thought of principally unlike anything else much like multiplying two negatives is a pretty unique principal seen by intellect so the function of mind is much more difficult to see and is to be comprehended for the doctrine to be properly carried.

It is said in the Sutta: 'it arises as one thing and ceases as another', 'it preceeds all things, all things are mind made', it is called 'the world' because it is that in the world which perceives & conceives the world.

Consciousness is a general term which is thought to include past, present & future instances of such or such consciousness thought to be coming into play as one thing and ceasing as another.

One can't think about consciousness as something in time. It is like the philosophy of measuring the position of an electron, it is not something you can observe as being here or there because that which is thought of as an electron is principally such that will have moved by the time you perceive it's location. With consciousness you likewise infer it's demonstrable coming into play and only think about it's function. You will see then that it's semantically tied up with conception & perception of all kind.

Hidden is the mind