Linus's VFS is where the 256 limit is hard. Some Linux filesystem, like RaiserFS, go way beyond it. If it was a big deal, it would be patched and widely spread. The magic of Linux, is you can try it yourself, run your own fork and submit patches.
LUKS is the one to talk about as the others aren't as good an approach in general. LUKS is the recommended approach.
Edit: oh and NTFS is 512 bytes. UTF16 = 16bit = 2 bytes. 256*2 = 512
Didn't when I tried when on LineageOS. I needed that bank app for work, so got a Pixel and switched to GrapheneOS. The bank app works, and it is useful to be able to on and off Google Maps (because of traffic routing and search, when compared to Organic Maps). But LineageOS worked better. GrapheneOS has more bugs and a small community.