diff --git a/docs/proposals/device-identity.md b/docs/proposals/device-identity.md
index e97de87..907349d 100644
--- a/docs/proposals/device-identity.md
+++ b/docs/proposals/device-identity.md
@@ -148,6 +148,40 @@ first, each when no bay has reported through it for a full inventory cycle.
 **`cmmid.txt` survives phase 3 regardless**, as the CMM backup-set path key. It
 is not on the deletion list; only its identity use is.
 
+### PXE and GE-Enforce prefer it too, not just the collector
+
+Phase 3 is not only "the collector reads a registry value". All three writers
+and readers move together:
+
+| Component | Change |
+|---|---|
+| PXE / imaging | writes `DeviceId` at enrollment instead of (or as well as) the file |
+| GE-Enforce | resolves device identity registry-first, mirroring how it already resolves the machine number |
+| collector | reads the registry ahead of the file |
+
+**GE-Enforce already made this exact decision for the machine number, and wrote
+down why.** `Install-FromManifest.ps1` resolves `TargetMachineNumbers` gating
+from the eDNC registry BEFORE `C:\Enrollment\machine-number.txt`, because:
+
+> the imaging-time `machine-number.txt` is written ONCE by `startnet.cmd` at the
+> PXE menu and is NOT updated on reassignment, so it goes stale.
+
+**`asset-id.txt` inherits that defect exactly.** It is written once at imaging
+and nothing updates it when a device is swapped, moved between bays, or
+replaced. The bay then reports an identity that was true on imaging day, and the
+collector - which now trusts that value FIRST, ahead of every other source -
+adopts the wrong device with no warning, because the value still resolves.
+
+That makes phase 3 a correctness fix rather than a tidy-up. A file that only
+imaging writes cannot be the top of a resolution order for something that
+changes during a PC's life.
+
+It also implies a reassignment path, the way `Set-MachineNumber` /
+`Update-MachineNumber` exist for the bay number: something that rewrites
+`DeviceId` when a device is swapped, and migrates any per-device state with it.
+Without that, phase 3 moves the staleness from a file to a registry value rather
+than curing it.
+
 ### Doing phase 3 early is cheaper than doing it late
 
 If the registry read lands before imaging is changed, phase 2 can write the