Well, on the devices I have which are constantly on Extras-devel, I've found the UI perfectly fine. I don't really have anything stand out in my mind as particularly bad/unintuitive about it. Well, that Automated Keyset Search or whatever - it's a bit unclear just from looking at it how it's supposed to work. But I suspect if I just started fiddling with it, I'd figure it out pretty quickly.
1. Separate it out into two packages, "pierogi" for the actual executable, conffiles, etc, and "pierogi-data" (nice, general naming that I see Debian packages use all the time) or "pierogi-keysets" or something more explicit like that, for the actual keyset data.
2. You could have pierogi automatically check for keyset updates and download new keysets.
[edit]But if they are hard-coded into the binary right now, then I would argue it would be must better from a design perspective to split them off regardless of what you did with the packaging for the repos, so that complexity is justified and ought to be in there anyway.[/edit]
So in short, I think your extras-testing criteria needs to be that it's "nearly-perfect" - you just need to think it's "probably not more broken than it was".