Looks good, as long you mount the cached one (which you do) you’re set.
Best mount settings for streaming varies from time to time. Depending on new features that are being added to rclone (like vfs-read-chunk etc)
If its an all in one seed box and plex server in one than those settings are good, maybe add cache-tmp-upload-path and cache-tmp-wait-time.
Chunk-total-size can be increased depending on the internal storage you got on your box. It will keep the set amount of chunks in cache until it reach the max. Then it will start to clean up the oldest chunks.