Downvoting stopped for a while, that's correct. When I coded the project I expected the downvote feature to be used more than it actually was, and required it to use all its dv power constantly. It wasn't used nearly as much as I thought, so in the end I was constantly filling up the list which caused a small burnout after a few weeks.
It's up again, still using all its power, but more at once when vp is high. That way I only need to intervene every couple of days, and we're better prepared for more people adding stuff more infrequently.

There's a small about text on https://curangel.com/, but that doesn't answer your question I think. The mission of curangel could very broadly be stated to "reward undervalued posts". There's a upper reward limit and some other hardcoded rules to prevent the worst of abuse (i.e. max 1 vote per author per curator per week), but basically we leave our curators the freedom to define it themselves. The daily compilation lists the votes by curator which makes them attributable, and they're all available on our discord if there's a wish to discuss a vote.

So I'm not sure if the voting meets your quality standards. The tail it votes is huge, so there will naturally be stuff in between where not everyone agrees. Also, the vote values posts finally receive are a little randomized and not at all dependend on the actual quality of that specific post.
For my requirements its doing its job well, spreading value on an active base of sincere users. It doesn't fix PoB by itself, but it's a useful addition to the much required manual curation imo.