the same method as with Plex Media Player, I suppose
except you don't have to replace/remove mpv.dll, the one bundled with JMP is ok
> Create mpv's configuration file in "C:\Users\<name>\AppData\Local\JellyfinMediaPlayer\mpv.conf" with the following contents:
input-ipc-server=mpvpipe
hwdec-codecs=all
hr-seek-framedrop=no