This controls creation, modification, and deletion of rows in the register-signal table, with the system-created default entry at index 1 permanently protected from modification or deletion. This immutable default row guarantees the gateway always has a fallback register-signal profile even if an admin's custom profile is misconfigured or accidentally deleted, so troubleshooting a broken custom profile can safely fall back to index 1 without risk of that baseline also being gone. An admin creating a custom register-signal profile for a new R2 variant would provision it at index 2 or higher, leaving the untouchable index-1 default available as a known-good fallback.