I never had any issues with the police or MOT, the indicators blinked much brighter than the side bulbs lighting them up.
Fully respect that but it is a grey area as a lot of things.
It's just running lights which are legal.
I have read, how true I do not know, that some bulbs shouldn't share reflectors which is the only downside.
Although the running lights aren't sharing reflectors until the indicators are on, so don't indicate and you'll be fine.
