1) installing both Plex and Plex/HT can have many undesirable side effects like them fighting for the same resources (mostly the Apple IR Receiver/Remote). That’s not a setup I can realistically provide technical support for.

2) many Plex users have customized their mapping and would not be amused if they had to do it all over again. But that’s exactly what would happen. Giving each of Plex and Plex/HT a Behaviour of their own would also mean that they no longer share the same mapping table.

Best regards, 
Felix Schwarz