I tried some with both “0.0/16” and “0/24” and it does work.
Not having the IPs show makes it a bit like working in the dark with eyes closed and takes a lot more effort to do what should be a simple moderating task. But it will be possible to do a work-around to make up for the set-back.
Now if we can get Mods to understand at least basic CIDR we should be OK