Bi directional sync is fundamentally harder than one-way. Mostly because it cannot be stateless otherwise you could never know the difference between deletions or new files!
Until rclone nativly supports something, there are many tools to do this...including one I wrote.
They are all on this wiki page.
I actually wrote two:
- syncrclone: Written from the ground up to support any two rclone remotes. Lots of options and ability to back up first. Extensivly tested on macOS and linux. Probably won't work on Windows out of the box but it shouldn't be too hard. I currently call it "beta" but it is likely going to be out of beta soon.
- PyFiSync: Originally written for local-->rsync but I later added local-->rclone. I do not suggest it for rclone anymore since I wrote the other one.
Two-way sync is also fundamentally opinionated with how to handle different situations. That's also why I wrote my own. But please do check out the wiki page for other options. They may serve you better!