Remote Control of Plex with my Android Phone?

Should I be able to use the Yatse remote control from my Adroid phone when watching Plex from my TV through Roku?

I have logged into my Plex media server with Yatse from my Pixel XL 3.

Not yet on the way I suppose you use (Plex client app running on Roku)

But you can stream directly from Plex to Roku from Yatse and have control. (Press the cast button when connected to Plex and select your Roku).