welcome to the forum,
does not work on mount command.
rclone, on its own, does not do that.
rclone simply provides the data that other applications ask for, such as finder, anti-virus and so on.
if finder tries to index the files and create thumbnails, that can be slow.
if you open a command prompt and try rclone ls ~/ghub:, what happens?
check out my summary of vfs caches
the dir cache is stored in memory, and once the mount is killed, the contents are lost.
might test --vfs-fast-fingerprint --buffer-size=0 --vfs-cache-mode=full
that might not be correct. the rclone debug log would provide the answer