that is for the vfs directory cache. caches the directory names, file names and some metadata such as modtime.
that should speed up navigating but often does not really matter too much.
to better understand that two caches, vfs file cache and vfs dir cache.might check out
https://forum.rclone.org/t/status-about-using-rclone-for-music-storage-playback-in-2021-access-times-improved/27648/34
wasabi is as fast as it gets, your mount should perform well, as does my wasabi mounts.
any reason to use that?
as for using windows explorer, it is terrible to use.
need to disable previews, content, tiles, etc - as that forces rclone to download the contents of files.
so try --network-mode and --vfs-cache-mode=full
what is the result of a speed test including ping?
it could be that high latency is slowing rclone down.