Upvote:1
The visa processing for UK is done centrally and usually there won't be much difference between the locations.
Waiting times are listed in this page - https://www.gov.uk/guidance/visa-decision-waiting-times-applications-outside-the-uk
Which is currently, within 3 weeks.
There is an option to keep the passport with you till a decision is reached, for an additional payment. Also, there is priority visa options available.
You can always request your passport back, in case of emergency travel.