OK, maybe a rare use case, maybe not?
I am divorced but my GEDCOM was of both families - I uploaded it, tweaked it, added new family to it etc and then decided my daughter (a budding genealogist) would be best suited to take over managing mum's side of the tree.
I had envisaged clicking on mum and swapping everyone above to my daughter, with one click.
However, the way the site lays out the page to do this is by surname and doesn't follow spouses etc lines.
I then waded through clicking each highlighted person "descendants of" and "ancestors and siblings of" to try and grab as many as poss.
I then have to export the remaining as GEDCOM, import into Family Tree Maker, print an "everybody" tree and pick out the non-linked stragglers.
Plus I note that all their names still appear in my Watchlist???
Bass-788 is mum, I need everyone above to have profile managers Mee-94 and Mee-92 and for everyone above to disappear from my watch list.