@Pathduck: Thanks, it's true, that deletes the synched data, which technically answers the question. The really annoying misfeature is that -- at least in my copy of Vivaldi (7.1.3570.47) -- the user is only offered this option after the sync has already been run, which in my case means after the out-of-date cloud copy has overwritten any changes I've made since whenever that version was set in concrete.
There's a sort of workaround in saving the entire, up-to-date Default profile somewhere; running the sync; resetting the damned sync data; and then writing over Default with the saved copy. Which is annoying as all get out.
Do you happen to know why this happens at all, that is, why is my current data -- password, bookmark, usw. -- is not updating the synched copy?
I feel that a really useful change would be a switch that allows the user to select which direction they wish the copying to go.
ta, maab