I have my Harmony Hub connected to my Shield via Bluetooth, using the Nexus Player workaround.
One thing that bugs me is that the only way to control playback in Plex is to use the on-screen buttons. There's no way to even map the hardware skip/ff buttons to a function.
Would pairing my Shield to the Harmony via IR allow me to use the hardware skip/ff buttons?
This was changed in a recent update:
https://forums.plex.tv/discussion/comment/1281387/#Comment_1281387