I frequently has issues with the BMG idler popping out of the guilder arm in the CW2 extruder.
This issue seems to happen to others as well, see for example this message in the Voron discord.
To hopefully fix this issue I remixed the guilder arm to have closed holes. This means you now can't click the idler in anymore. Instead you need to insert the pin from one of the sides and only then insert the idler.
The author remixed this model.
Closed pin holes for the BMG Idler in the CW2 guilder arm