Ah yea, I had and just forgot to link it, but there’s one linked to the issue I raised here.
The PR actually wraps up another fix where UsedSpace was getting constructed twice and the global used_value wasn’t syncing between chunk stores from what I coud tell. Since the former affected the implementation of the latter, they got a bit interleaved.
Ah ok thanks, that’s eventually what I figured must’ve been the case 
As for an API for changing reward key, that’s pretty much the context. I’m currently working on a pet project to start implement just such a thing, which was the original motivation for this thread.