I've been nervous about all the major changes I've been making to the UI, hoping to get a little more feedback about them. (And yeah, I keep wanting to add more tweaks too...)
Now that I think about it, here's one question I have about the current system: once you've pushed an app up to Extras, there's no real way to perform maintenance on it. That is, I very much like the idea of having a "stable" code branch and a "development" code branch. For example, once I pushed 1.0.0 up to Extras-testing, I went ahead and started tweaking the UI in version 1.1. However, there's no reason I couldn't back-port new keysets into the 1.0 branch (and I still have the 1.0 code sitting on my computer here); however, I see no (easy) way to maintain two different codesets within the Extras mechanism.
Ultimately, you've either got to push up a nearly perfect app to Extras-testing, or hold off on making any major changes to the app in Extras-devel until you're fairly sure you won't need to push up any fixes. I've been following the first path, and have been leery of pushing up my code until it's in a fairly stable state...