Binding to Custom Component Methods

Personally, I would never use parameters of type UDTType, for all of the reasons in my post you linked to. Not sure if I understand your reference to the Python expression, but for the Window component bindings, you would use the expression language rather than Python to read the tag values, e.g.:
tag({RootContainer.DevicePath} + ‘/Temperature/PV’)

I found this eliminated all of my performance issues, once I moved away from UDTType parameters and started using this method above instead.

Just my 2c