This is a problem for many of us. We run out of space in the Storage Pool and we do not know there is a problem until a disk fails or we see storage repair jobs failing. Is there a technical reason why Microsoft is not able to just reserve the equivalent of one capacity drive per server, up to 4 drives automictically at Storage Pool creation as described here
https://docs.microsoft.com/en-us/windows-server/storage/storage-spaces/plan-volumes#reserve-capacity?