Well, yeah. Crypt is a feature of rclone. It has nothing to do with docker. All docker does is package the program in a container. The docker version might use an older version of rclone before the crypt feature was added, if that's what you are asking.
The only real difference between the docker and the plugin versions of rclone, as far as usage goes, is that because of the way docker works you cannot share a mount with another docker. So for instance, if you are planning on using a rclone docker encrypted mount with Plex, you will need the rclone plugin.
Cool thanks. That plex example is what I was looking at. I just using it to backup so I can stick with the docker. Thanks.