Yea the 500 thing is a funny one. Fortunately it's now gone on Desktop (but not on Android) https://github.com/deltachat/deltachat-desktop/pull/5451.
> mobile
Yep! treefit (npub1t0n…7d8g) has made it work: https://github.com/deltachat/deltachat-desktop/pull/4871. Although we don't even provide `.apk`s.