If "read belt length" is checked, and then all wires are disconnected, the belt segment is still connected to the circuit network (although it's not)

because the belt is still connected to the hidden combinator, i used to have a wire count check against that but that broke when it is a ghost and would lead to really unstable copy paste behaviour, i do not plan to fix this (because i am not able to), mine and replace the conveyor to make it go away

Fair enough, thanks for the quick replies!

no problem