I'm thinking mostly about the staff interface here, since it's unrestricted currently.
Actually, it looks like this one is configurable. You don't get it out of the box, but you can configure "Default checkout, hold and return policy" to use "patron's hold group" for "Hold pickup library match". It's not very intuitive and the word-choice doesn't match the rest of Koha (ie "local hold group" and "Pickup location" respectively), but... I guess that's life. That setting got me where I needed to go, so good enough.