Created a new replacement dust adapter for my circular saw that replaces the original one. The original didn’t fit my Nilfisk Multi II 30 shop vac. Now I don’t need to fiddle with the adapter I first made.
Sharing if someone has the same combination: https://makerworld.com/en/models/996710
In my experience the torque in the part can be reduced by commiting the bent nozzle part of the vacuum and connecting the hose directly. It should come apart easily. Doesn’t solve the problem completely but worked well enough for me.