I’ve been using transitional multifocals for a few years now. (Our OP is from the UK so terminology is different). Transitional means the tint darkens as required.The transitional lenses don’t darken enough on the flight deck for my liking). Multi focal gives me distance, short range, and reading in the same lens.
I used to slide my Transitional Multifocals over the top of my Sunglasses when required.
I’ve recently had a pair of Sunglasses made to my mutifocal prescription and so far all great.
I do think the particular lens design of prescription Sunnies can play a big part in you’re particular outcome.
You will need to speak with your optometrist and if possible look at some visual examples of what they can provide.
I have friends who’ve tried the same with different providers and had not so good results.
And obviously don’t get polarised
cheers.