> is using 0.0.0.0/24 an acceptable solution
I don't think so. If you want to reach any 192.168.0.0/16 except 192.168.0.0/24 from the server you need to build the Allowed IPs in reverse there is no direct formulae to mask one network.
Then it will be: 192.168.128.0/17 + 192.168.64.0/18 + 192.168..32.0/19 + 192.168.16.0/20 + 192.168.8.0/21 + 192.168.4.0/22 + 192.168.2.0/23 + 192.168.1.0/24.
The Allowed IPs on the client will stay the same: 192.168.0.0./24