Need to bulk associate Activities with a Deal

Thirding! I recently found that when creating a new Deal, you can choose *then* which Contact and Company activities to associate with that Deal by default - cool right? Every time I add an activity to Camille Client, it will always be associated with her Deal, but only if I’ve *just now* created that Deal.

But the same CAN’T be done for existing Deals, so we’re left with manually associating *every* individual Contact/Company activity with the appropriate Deal. To me it seems absurd that it can be done for new Deals, but not existing ones. Support suggested I submit an idea here, but I haven’t had a lot of success with that so far, and this seems like a no-brainer, and almost irresponsible for them *not* to undertake it as a feature request right away.