What you requested a year ago would be most useful today. Storage devices do not take well to having their mounts yanked without proper notice. Did you ever get an answer to the question of how to defer activation to the next reboot?

Quinn, thanks for the cogent explanation. I feared my project would stall waiting for entitlements to debug. There do appear to be some issues with the approach you outlined (as a non-expert, of course). It appears that the App ID page has not been updated for several additions to DriverKit. Specifically: userclient access com.apple.developer.driverkit.userclient-access promiscuous userclient com.apple.developer.driverkit.allow-any-userclient-access BlockStorageDeviceDriver com.apple.developer.driverkit.family.block-storage-device SCSIPeripheralsDriverKit nowhere specified but perhaps com.apple.developer.driverkit.family.scsi-peripherals It appears to me that without these entitlements supported, you can't build and debug sample DriverKitUserClientSample, SimpleAudioDriverExtension or, most important to me, my project -- which needs userclient access and SCSIPeripheralsDriverKit. I look forward to Sharing and Enjoying your response. John Brisbin

A few days ago, I reported substantially the same issue as feedback item FB11064423 (which you probably cannot see). Having no workaround to allow debugging until real entitlements are available, in some indeterminate time, will put a kink in my development, for sure.