Control Groups Overriding Unit Handover in Trade-for Quests

Hey folks,
Dunno if it's common knowledge in the community yet or not, but in the Trade-for quests, such as Trade for Mosaic Tile (Argos, 20, 12 hour repeatable), you can force the game to not switch unit ownership from yours to the ai ally at the next checkpoint, by binding the units to a control group, and on the first group you do this to, spam the group and another as the boat reaches the next checkpoint.

I have demonstrated it a couple of times in this video

I was just concerned that it may be an issue in future quests that aren't quite so linear or easy, that feature handing over units to another player.