Hey Mark,

Yes, Python 3.8 is now supported.  The module behind the scene which actually communicates between Python and the ZOS-API is a module called pythonnet; Zemax itself does not have any special code to handle new versions of Python.  When the templates were first created, this module itself did not support Python 3.8 so we couldn't support it in the templates.  Since then, pythonnet has updated to work with Python 3.8.  For future releases of Python, the compatibility will be based on when pythonnet itself supports the new version:

https://pypi.org/project/pythonnet/