Briochee

I'm not sure what you tried already, but the only thing you really need is this tool here.

You can compile the routine directly to your ROM or you can compile it to a separate file and copy/paste it in. The Tool only has like five options so it's really simple to use.

The only other thing you need to do with my routine first is put the offset where you will insert the routine after the ".equ ROM, 0x08" part at the beginning. So, if I wanted to put it at 0xAABBCC, I would have ".equ ROM, 0x08AABBCC" at the beginning.

I think your best bet for determining compatibility is to compile both into a clean FR rom and play around with surfing. As far as I know, CFRU doesn't touch surf so it should be fine

I've stopped binary hacking, but if you submit sprites to the post I'd be happy to update the repo! I think it should be compatible with CFRU, although I haven't touched that in a while either haha