I need to do this myself, and I have nearly the same lenses (35/2, 50/1.8, 100/2)
I can't afford to have all L lenses, and I need to decide which focal length is my "favorite" ... for me it'll either be the 35 or the 50. I hope canon makes an affordable RF 50mm.
I here ya, I have one L prime lens and several L zooms. I would really like the 85 L, 100L, and so on but cant afford them. But I keep coming back to the smaller primes. They really shine on the mirrorless cameras and they are lighter to carry around. I think the 35 will be the go to lens too, with it being one of the only non L primes lens with IS it's great in low light to get sharp images.