Hi again :)
3 simple things^^

1. Server crash while dying in the "Wide Desert"
   I can't give you the crash log, because no access to the server, but i can describe my process:
   -> I joined the desert via book, I found a Battle Tower next to my spawn, I cleared floor 1, I went down to floor 2 and a Skeleton and a cave spider attacked me (I had the poison effect), the Skeleton killed me with an arrow -> I died and saw me disconnecting to the multiplayer screen with the message "server closed"
   (if you need the crash log, I try to get it in the next days)

2. Is it possible to add a second keybind for a quick change of the mining assist "modifier" ?

Edit: 3. Crash in the Randomite ore item black list ingame config screen. (I think, the list can't handle "Immersive Railroading" icons)

MC: 1.12.2
Forge: v2584
Cavern: v2.3.1