Working great! Thanks! I've made a simple batch file that copies over the DLL I run whenever Plex updates. Make it in Notepad and change the extension to .bat. Then run as administrator.
@echo off
set "source=C:\Program Files (x86)\SVP 4\mpv64\libmpv-2.dll"
set "destination=C:\Program Files\Plex\Plex\libmpv-2.dll"
echo Copying file...
xcopy /Y "%source%" "%destination%"
echo File copied successfully!