Day time - Personally I see no logical reason for using main beam in the day, particularly in traffic, as it will surely just produce a blinding white glare (particularly LED's) that will cause difficulties for other road users (including pedestrians) to estimate your speed, distance, or position. If it's attention you need for safety then the 3 points of light or yellow fogs will make you stand out better, anything that is different from the norm or something that will make a driver look again. You don't need something that will blind them, they're blind enough already!
This article by Andrew Dalton, a bike riding Solicitor may be of interest - https://www.whitedalton.co.uk/motorbike ... torcycles/
As an afterthought, it's always bemused me when I'm behind a car at night, just me and him, in an unlit derestricted road and with no traffic ahead or oncoming and he's doing 40 mph on dipped beam, presumably because he can only see about 25' in front of him. I can't overtake him 'cos I can't see where the road goes, but if he switches to main beam he can see further and will therefore be safer, and from a personal point of view he's immediately improved my view and I can get past him... as I said, just a thought.
