This addon is made for rigging robots and other non flex stuff. The addon will add vertex groups with all vertices to selected objects.
When adding this to blender remember to zip the python file so you can add it in the prefrences. Then you should see it on the right and remember that all vertex group will have the objects name as their name.
I made this for blender 3.0.0 so if it is not working update to 3.0.0