One thing to be remembered about these Zs, don’t unplug them and turn them off for long periods. When my 3100 broke a belt I left it for almost a year. All the heads were dried, with a blank nozzle check, and I had to replace all six at a cost of about $430.00. Recently someone offered me a z3200 that was in really good condition, only problem was they did the same thing. Soaking the heads didn’t work, so I passed.
You can leave these printers almost forever plugged in without use, but unplugged for a long time will cost you. The good thing is the ink doesn’t dry in the lines, only the heads.
There's probably some variation to that too, depending on where/how it's stored. I had my z3100 in storage for about 1.5 yrs (thanks to poor planning around moving house). It was in climate-controlled storage and bagged inside the original plastic wrap and styrofoam "crate". I was really nervous about it's condition the whole time, but the manual said nothing more was required for storage.
When I finally got it out of storage, I had to burn through a lot of ink and paper doing purges, head cleans, and diagnostics plots, but eventually it sorted out. The MK-R head was the only one that wasn't stellar, and it eventually had to be replaced some time later. (No surprise since it's nearest the spittoon crud. (Edit: right-side service station, not spittoon.)) I tried my best manually cleaning it, but just wasn't enough I guess.
Was pretty happy overall with how well it came back, since it could've been much worse like you said. Rather not do it again though!