Using the SPT on MacOS Catalina requires granting Input Monitoring privileges. This wasn't very intuitive to find, as it will just throw an error running sdphost without these privileges.
Hope that helps somebody!
Hello jackking,
thank you for pointing it out. BTW it is also mentioned in the documentation bundled with the tool, see chapter "5.7.1 Enabling USB Connection on MacOS"
Regards,
Libor