[ar-jan]

> ever tried to use it with ~10k items?

Yes, around 13k currently. Startup is slow, but I keep it open so that doesn't matter much. With Zotero 6, speed isn't great for general usage, but workable. Zotero 7 (beta) however feels very fast. I've switched to it already -- most plugins haven't been upgraded yet, but (at least currently) you can switch between v6 and 7 since there's no database updates involved.