I noticed earlier that selecting the "collections" option, when quickstocking, doesn't happen to include the Minion Zoo! And that's quite strange to me, since it's included in the Games tab as a "collections" feature. I think it's rather cute to collect minions in the same way you collect plushies and beanbags, it gives me something to use them for instead of just selling them.

Could we have that functionality added, perhaps?

I'd assume it'd just accept the minion being put there regardless of whether you already have that minion in your Zoo or not, since you can store multiples-- similar to moving something to your Vault or another shop/gallery.

This is already implemented but there is a setting that disables it which can be found here. The setting is "Do NOT quick stock to Minion Zoo when quick stocking to collections" so it needs to be turned off to allow minions to quick stock to the zoo.