At present, if a family is nested inside another family, and a flipped version is required to be accessible from outside, to show differing handing of a part, the only way to do that is to have a visibility control on the normal and the handed versions of the object.
Given the possible combinations, you might need 4 vsibility parameters in order to do it.
This seems a very complex way to do something that should be inherently simple.
So, could we have parametric controls of flipping please.
Flipping should also be able to be done vertically (what goes up might need also to come down), something I'm amazed has never been implemented, it's crazy that to invert something might require remodelling it.