This may not help, but here goes. Deleting SMS messages on one device never gets synced to another device for me. I rarely use iMessage, but I expect SMS to als

This may not help, but here goes. Deleting SMS messages on one device never gets synced to another device for me. I rarely use iMessage, but I expect SMS to also be handled the same way (since I have SMS forwarding setup and get the same messages on multiple devices, with all of them tied to a single Apple ID).