It is my goal to update the workplane, because currently, I can only create a new object (with a new workplane) and copy all parametervalues over which does not seem to be a clean solution at all
Looks like setting the workplane may only be available via postable command, which means not really doable en-masse for families the way you’ve requested.
Recreating the family in the location with the correct workplane, copying over the relevant parameters, and deleting the previous instances is the route I’d go (not as big a limitation as one would first think).
