What is missing from my subclass of propgrid.PGProperty?

Addendum: In a nutshell, I would like to know if it is even possible to subclass the PGProperty baseclass at the current state (wxPython 4.2.2, Python 3.13.2) - not unlike this question about subclassing a GridCellEditor: infinite-recursion-subclassing-gridcellnumbereditor.