Check brave history and you will see the amount of controversies they have. I personally wouldn’t believe anything Brave says.

I remember an announcement that the feature enabling remote viewing (outside of network) has/will become a paid function on Plex. But I haven’t followed it so don’t know all details

If I were you, I would try to disable some/all of the image features your TV has in settings. Could be those settings that create soap opera effect.

I’m not 100% sure but I have always read that playing movie at higher frame rate than source doesn’t make video looking better. To get best results, it is adviced to have your screen frame rate matching the one from source. That being said, can’t tell you how to achieve this on linux since I only watch stuff on TV using shield TV as a player.