what do I need to do to make one of my accounts the default "keep" for de-duplication?

I’m trying to use de-duplication to remove duplicates between two of my calendars. My primary calendar is served by memotoo.com, my secondary calendar by Google. I have tried every combination I could think of – order of account addition, account names sort order, Google data API versus Caldav, but I cannot my my primary calendar show up as the default “keep” target. With some 2500 duplicates between them, with 5 clicks to swap the “keep” around (select duplicate, select secondary, remove, select primary, keep), I’d prefer the default “keep” to be the calendar that has the least amount of reassignments.

Hi, deduplicator uses as “default” folder your selected folder in left-side bar. We do not plan to make any default folders for it.