Okay, I see I misinterpreted the "details/prompts" part of the requests. So I cannot restrict my requests, that's okay.

But the example forms all specify some kind of plot prompts, and I cannot fill those if I don't write fic. I would simply feel uncomfortable with a request like that, because it would make me feel that I can't make what the requester expects.

If the requests are all as open as just stating fandom(s)+pairing, then that would be okay, I guess? I'll have to think about it.