I currently have (have had for 5 yrs +) transition lenses and they do not darken behind modern face shields, as pointed out, because the shields block the UV rays. Same thing in the car's, UV rays are blocked so no worky. I used my FSA bucks and had a pair of sunglasses scripted out, no line bifocals with the 'reader' portion focal point at like,,,,22" instead of the standard 18" (I think). That way could see the gauges better, also, because I don't need the reader part to read, asked they make that part a low as possible since most of my viewing is eyes up, looking out.
Yeah, a pain to manage/carry around a pair of sunglasses then another pair of glasses, but,,,,,I live with it. Plus, I prefer dark sunglasses anyways, the transitions only get their usage outside on cloudy'ish days, and/or when wearing a ball cap, other wise, they aren't dark enough for sunglasses use for me personally.