Hardware transcoding support Raspberry

I was able to install WinTV Mono HD tuner on my Rapspberry PI3 all works but due to transcoding it is not usable (transcoding eats all CPU power). I have enabled MPEG2 hardware transcoder (tested with omxplayer) but I do not find any solution to force Plex in using that. Is there a solution for this? Is there a client that would not force me to use transcoding?