This is an issue for us as well. Some of our managed devices are in labs and because of timescales we tend to deploy the current OS in Aug. The new OS releases in Sep but we cannot upgrade during the academic year so must wait until the following Aug. It's vital that we can install point releases to ensure security during the year. I completely agree with the proposal from the OP. Split the deferrals into major & minor releases. This would allow point releases to be installed swiftly (after testing) and major releases to be deferred until we could upgrade the labs during the defined point in the academic year. Our service relies on software being consistent (aside from security fixes etc) as course notes are tailored to an agreed software deployment. Personally I 'd prefer to be running the latest OS sooner but Apple's release schedule does not work well with the academic year.