There may be some alternatives to mitigating that risk: protect the files on USB so only the backup application can write data… Configure rclone to sync on a delay (this way youd find out if your USB files were deleted accidentally before the rclone sync)… Configure lifecycle policy on wasabi bucket to retain deleted items or changed items for a certain amount of time… Etc
I’m just trying to discourage using Duplicati to back up Duplicati backups a second time 