Closing off Shared Doors? - 4-Unit Multi

[Nick Mace]

Hello!  First time poster, long time reader...

I'm doing a 203k (limited) on a 4-unit multiplex for BRRRR. I'd like to keep my out of pocket as low as possible, but don't want to shortsightedly sacrifice value adding improvements. So, this is essentially an old Victorian that was converted to a 4-plex. Between 2 first floor units (front and back) is a standard interior door, with opposite facing deadbolts. I want to address this mostly for perception of privacy/safety reasons, as well as noise mitigation. My question though... is it beneficial to replace it with a better door (for future re-configuration flexibility), or to just permanently seal it off? If I were to seal it off, the plan would be to use the resulting alcoves created from the current hallway for in-unit laundry (a big plus in this building's rental market). A caveat to the laundry idea is that, while the electric has been split off, the heat and HW has not. Though, the plan is to separate the remaining utilities, I'm not sure there's enough in the 203k(L) budget to do it now. But, worst-case.. another storage closet in the meantime I suppose.