You’ll be stuck modding with Seimitsu buttons for LED’s until someone figures out the dimensions and spacing on the new transparent buttons. The currently available LED mod parts were designed for use with transparent Seimitsu buttons and preliminary reports suggest that the LEDs will have to be redesigned for the Sanwa’s.
Oh, and just because the stick is an SA model doesn’t mean you can’t swap out the parts for Seimitsu parts. It’s just that most people don’t bother because of cost and the perception that “Sanwa is better.”
It’s all opinion and preference, really.
FYI, the real problem with the V3 SA is that the new case design makes it harder to fit in new parts. The space is really tight in that case. Part of it has to do with the faceplate being permanently screwed onto the base. You can’t easily access the screws that fasten the faceplate unless you peel off the sticker (which ruins the stock art). In the previous SA models, you could remove the faceplate and it was much easier to swap out parts and do mods. With the V3 SA, you have to open the stick from the baseplate. That was the same case with the regular HRAP 3 unless you modded the case to be able to remove the faceplate from the top of the base.