I am simply using :-
MyCat = CatParent()
This creates either an invisible CatParent or one with no scale, which is to be expected as I haven't told it how big I want it.
Altering the CatUnits Scale at creation or afterwards doesn't alter the size of the Parent Hub and I can see nothing through Showproperties to control the Hub scale.
I'm probably missing something obvious here but forgive me as last night was a late one but for all the right reasons :)