Getting started with Mountain Duck

[milli foo]

Howdy - I've tried searching, but not finding this particular question, so apologies if this has been answered before.

I have several terabytes up on Dropbox, which is also synced locally on an external hard drive. With Dropbox's recent announcement (*) that they're discontinuing external drive support, I've been hunting around for a solution, and Mountain Duck (MD) seems like it fits the bill (no pun intended).

Since I already have aforementioned terabytes both in the cloud in and on my local disk, I'd like to avoid downloading those terabytes just to get them local in MD's DMG. Is there a way that I can just copy the local files into the DMG such that MD then syncs and tells DB that everything's a-ok, no need to re-download these many terabytes again?

Note that I did try the experiment of copying over 25GB directly onto MD's DMG --- it turned around and told DB cloud to delete those very same files in the cloud -- then uploaded them again. So clearly that's not the way to do this.

(*) https://9to5mac.com/2023/02/14/dropbox-macos-external-drives

Note: after much complaining, DB has now said they're pausing the rollout of the new client that kills external drive support while they re-explore the issue. Still, I've lost faith in them, and like the idea of MD letting me sync files with one of several different cloud providers.

thanks!

-foo