Depends...
However there are a few who consider that leaving the lock "reserves the space"...... that is unacceptable.
Is this acceptable behaviour? Would the council or police ever cut it off if left for a day or two?
I figure I'd have to remove it if someone else gets my spot first, but does anyone else do this to save lugging around heavy locks?
I leave a spare cable lock at my son's school for the occasions when I forget his D-lock. (I only lock it with the cable lock long enough for me to cycle home and get the D-lock.) But I usually carry my D-lock as I don't know when I might pop into a shop.
I think the main downsides from leaving a lock attached to a stand is that the weather can get to it over a long period of time, or that those with less than perfect intentions can get to the lock and tamper with it in the hope that might leave your bike not properly secured.
Outside the council offices in Rotherham, they have half a dozen, individual, steel cycle lockers. All you need to secure your bike is a padlock. One of these was unoccupied with 'reserving' padlock on it for months.
I don't think you'll have any problems leaving a lock on a stand.