PSCM Swap (2019 to 2020 Rack) - As-Built Reverting and Steering Mode Offset Issues

[v8stangram]

Hi everyone,

I recently replaced the steering rack on my 2019 Mustang with a newer unit from a 2020+ model. I’m running into some frustrating coding issues with FORScan that I hope the experts here can help me untangle.

Old Rack (Original 2019):

Part Number: JR3C-3F964-AF

Strategy: JR3C-14D003-AA

Calibration: JR3C-14D004-BD

New Rack (Installed 2020+):

Part Number: LR3C-3F964-AC

Strategy: LR3C-14D00x (2020 series)

The Issues:

1. As-Built Persistence (Auto-reverting codes):
Every time I try to write the GT or GT350 parameters, the PSCM seems to "auto-correct" or reject the values.

If I write 0201 in 730-01-01 (GT), it automatically reverts to 0200 after a reset.

If I write 0601 or 0301 in 730-01-02 (Tuning ID), it consistently reverts back to 0001 (Base/Rental tuning).
It feels like the LR3C firmware has a hard-coded integrity check against my 2019 VIN.

2. Steering Mode Offset (Mapping Shift):
The only way I can get the toggle switches to work is by using 0100 in the second block of 730-01-01. However, the modes are completely offset when looking at the PIDs:

Physical switch on Comfort -> PID STEER_FEEL reads Sport.

Physical switch on Normal -> PID STEER_FEEL reads Comfort.

Physical switch on Sport -> PID STEER_FEEL reads Not Used.

3. Missing "Module Configuration" Menu in FORScan:
In FORScan, I only see PSCM Module Configuration (As-Built Format). The "friendly" text-based PSCM Module Configuration menu is completely missing.
Because of this, I don’t have a way to run the Central Configuration Learn or any calibration procedures other than the basic reset.

My Questions:

Is it normal for the "friendly" Module Configuration menu to be missing when swapping an LR3C rack into a 2019 car?

Is the LR3C strategy simply incompatible with the 2019 CAN-bus signals for steering modes?

Do I need to perform a firmware "downgrade" (Strategy flash) to a JR3C version to make this rack behave like a 2019 unit?

I’ve tried writing with a battery charger connected (maintaining 12.6V+), but the results are the same. Any insight into how to get the GT350 tuning to "stick" on this 2020 rack would be greatly appreciated.

Thanks in advance!