skip_undo_entry is not publicly exposed at the moment, so please wait until I update update_card/note to add it as an argument in the next rc. merge_undo_entries() shouldn’t be required if you have all the notes in advance, as update_notes() can update multiple notes at the same time.
For startup actions, you can do any raw SQL change like ‘update col set mod=mod’ to clear any undo entries.