I just stumbled across this.

Insteon Command 0x19 "Status Request"
Returned ACK message will contain the On-Level in Command 2.
Command 1 will contain an ALL-Link Database Delta number that increments every time there is a change in the addressee’s ALL-Link Database.

If command 1 is accurate, then as long as the increment number matches the last full scan conducted by MH, we know that the database on the device still matches what is in MH.  In that case, we would not need to scan the device.  MH just ignores this number right now.

"Scan all device links" could be changed to, "scan all device links that have changed."  This would be faster and would risk less possible errors.

Has anyone ever tinkered with this before?