Forge: 1.18.2-forge-40.1.93
Quark: 3.2-358

Quickly spamming with item share causes minecraft to kick you for spamming.
"[playername] lost connection: Kicked for spamming", player disappears... but is still connected, can place blocks (but not destroy them), kill other players etc. while being invisible and not appearing in [tab] menu.

When just "normally" spamming with text server kicks you properly.
However if you hold [shift + t] and move mouse over items in inventory server "kicks" you while leaving you in-game. But mobs and such ignore you, chunks arent loaded either.