Limiting parallel repository actions:

Running kopia-UI v0.10.7 on Arch Linux:
I have one Backblaze B2 repository, Wasabi and a local repository. When I reboot and Kopia starts it does snapshots for all of them at once and it can eat 15gb of ram of my 32gb. Also the B2 repository during a maintenance uses so much cpu the desktop is stalled on a Intel Core i7-9750H.

Can I limit repository actions to one at a time?

I suggest to change this workflow. Instead of doing 3 times the same backup, you can do it only once, to the local backup and then, when it’s done, use kopia sync-to ...provider to synchronize repositories with local one.