relays and clients can apply GrapeRank too, not just individual users. so yes, you're right, we need it on relays too.

we have very minimal WoT on relays now, just based on follows of follows. GrapeRank is baned on, well, anything that the user wants. go ahead and build one based on kind:1 notes with GIFs if you'd like and call it GIFRank.