The early hacks we had (thanks to Jun) were on 1.6 -- yes, back on 1.6! -- don't apply anymore, and would need quite a bit of rework. And backporting the repo API and filepicker from HEAD is crazy, as it's intertwined with the filestorage API and the db changeover.
Are there any more modern patches out there? Or perhaps a hook I could (ab)use...?