Originally posted by avatar.zero:

"Local"/"Cloud" aren't separate saves, but rather where you want the save for that particular world/character to be kept. Changing your selection moves the data, not copies it. If you want to save-scum like that, you need to keep them on Local and manually make a backup of the relevant files.

Thanks, I was doing that in earlier save modes but misunderstood advice given here when they added the local/cloud option. I'll revert to my original manual method as you suggest.