I've sent the project owners two messages so far. On GitLab, they want a prospective proofreader to translate first. I did that, only a few strings, but they didn't put any limits on it, so I count it as a translation. I then sent them the messages. They have one Dutch proofreader listed, however, she hasn't been active in a while. The translations that were bad were older ones, and I gave them a minus vote, to some I commented. The translators now seem to be quite good, so there's not much hassle there. I would love to go through all of it, but I only vote for those I see if I have the time, because it's quite a lot that has been translated already.