The original belt-drive Z-axis demands a light touch and appropriate feeds and speeds — it’s something of a balancing act to ensure that the machine is always engaged so as to take a cut and form a chip rather than deflect and rub — it’s quite fast for Z-axis movement though, so if working with yielding materials can actually be quicker for a given cut.
I keep a belt-drive Z-axis SO3 Standard at my mother-in-law’s and use it when visiting, and so long as I remember not to send a file which has feeds and speeds tweaked for production on my SO5 Pro, it cuts fine, just takes a little longer.
The other concern is that a precipitous loss of power can result in a plunge/lift which will cause the motor to function as a generator pushing current back up to the controller possibly damaging it (EDIT: though as pointed out below, this is unlikely — it’s a short distance and not that much current) — I make it a point to park the machine, moving the machine to the middle of the Z-axis motion (I set up a Quick Action for this) and put a block of foam under it — I pretty much have to though because my machine is on a folding stand: