PHD2 does not use the ASCOM Chooser to select either telescope or camera drivers, instead it apparently reads the ASCOM Profile store in the Windows Registry to get a list of installed drivers and intersperses them with native drivers.
This solution does not scale to support ASCOM Alpaca devices. Does PHD2 implement code that uses the dynamic Alpaca Discovery protocol to add Alpaca devices to the lists of scopes and cameras?
If not, I would suggest providing a way for users to invoke the ASCOM Chooser to support Alpaca.
Thanks,
Rick Burke