Yes, special vdevs expand like any other mirror vdevs do. You may need to use zpool online -e on the vdev to trigger the expansion after you replace the last small drive in the vdev, but that’s easy enough.
You don’t need to scrub after replacing vdev members, because the resilvering itself forces checksum validation on every block in the vdev. What you might want to consider is running a scrub before removing any member disk, so that you can make sure not to orphan any undetected corrupt blocks that you could have repaired, if you hadn’t already gotten rid of your only source of redundancy! 