Not entirely sure I've understood what you're asking, but if you're are wanting to put normal (as in NOT reflector) LED E27 screwcap lamps in place of R80 LED reflector lamps (also E27 screwcap), then there should be no problem. I'm guessing they're recessed in the ceiling downlights so you will lose a bit of the light that goes up into the ceiling of course.
If you mean going back to incandescent lamps instead of LEDs, then the R80 fitting should be designed for the extra heat as they're an old design that predates LED lamps.
I know little of epilepsy - is it the colour of the light that's the issue or that some LED's 'strobe' - i.e. they go on and off 100 times per second? If the latter, you could try different LED's as the non-dimmable, better quality LED drivers store more energy to keep the LED lit during the zero crossing of the A.C. supply