Yes, and then your main kernel image is no longer on ZFS and you lose the ability to reliably roll back your root dataset. Everything is a trade off. I reboot m

Yes, and then your main kernel image is no longer on ZFS and you lose the ability to reliably roll back your root dataset. Everything is a trade off. I reboot my workstation once a week for a kernel upgrade, so an extra 2 seconds of boot time isn't even a consideration.