My Plex mount is read-only with polling disabled and no cache (as you know). Before my daily scan, I always run rclone rc vfs/refresh recursive=true --drive-pacer-burst 200 --drive-pacer-min-sleep 10ms --timeout 30m --user-agent *******
My current mount command is rclone mount --attr-timeout 5000h --dir-cache-time 5000h --drive-pacer-burst 200 --drive-pacer-min-sleep 10ms --no-checksum --poll-interval 0 --rc --read-only --user-agent ******* --vfs-read-chunk-size 1M -v
@RicarSeg If this is your initial Plex scan, things will be slow. That's normal. Make sure you use the Plex Series Agent, not the legacy one. Triple check that all the extra stuff is turned off (intro detection, thumbnails, etc.).
You also never said what exactly you mean by "slow". Maybe you can expand on that a little, so we have an idea.
EDIT: To give you an idea of how fast a scan can be, it takes about five minutes for me to scan my entire library of about 950 TB.