Hi, I've used rPi B in the past (yes, gen 1!) and am playing with Plex again. My current big issue is transcoding, the system doing the plex serving has CPU pains even with transcoding 720p content and my Fire TV Stick 4K does not seem to have DirectPlay features for MKV with AVC/AC-3. I read on Reddit that my options may include the Roku Ultra but also RasPlex on a RPi 3B (non plus). There are a _lot_ of options as far as RockChip boxes listed in the downloads section and no comparison guide that I have found, and the wiki article on rockchip is empty. I'm already interested in the new hotness of the RK3588 but that's not supported and probably won't be for some time.
Is LibrELEC on a RockChip a good option for DirectPlay or at least DirectStream from Plex? If so which option is the best bang for your buck, as in, you can actually buy the board not 4x MSRP.