plexdrive looks like a very tightly focused tool:
- use of fuse limits support to a sub-set of *NIX systems + MacOS
- Only supports Google Drive
So yeah, I can see creating a new tool, rather than crafting a limited feature set into a cross-cloud service/OS tool like rclone. It would likely be really confusing from a support POV to have these features in a “beta” mode in the broader rclone app, not to mention any issues from the added code in the fairly stable rclone codebase.
Also: You don’t have to message the dev. Every Github comes with an issue tracker for exactly these kinds of questions (as well as general problems), here’s plexdrive’s. If they prefer questions elsewhere they’ll usually tell you. Using it means you can ask this question on an open forum where others than the dev can reply – just like here.