I know a huge wishlist item for me (besides separate tack/feed rooms), is a big basin sink and counter in the tack and feed room, ideally with some cabinets. It’s just so much easier.
So, totally hypothetical, if I was “forced” to have a shared tack/feed room, that would at least mean I could save money on the sink/counter/cabinet set up, since I’d only need to install one.
But again, this barn is not being built any time in the forseeable future.