[Request] Samsung Galaxy Book2 Pro (P12RGG, i7-1260P + Arc A350M) Unlock BIOS Rebar

[RafaelLVX]

Laptop is a Samsung Galaxy Book2 Pro, i7-1260P + Arc A350M dGPU, BIOS P12RGG (AMI Aptio V / AMITSE, Samsung's own graphical skin on top). Arc needs ReBAR or it's basically unusable - GPU-Z shows "ReBAR enabled" on the Arc device but that's misleading, Intel Graphics Software keeps telling me it's off, and performance is bad enough that letting a program actually load the GPU can hang the whole machine.

There's no 4G Decoding / ReBAR option in Setup, no Chipset submenu at all - just SysInfo/Advanced/Security/Boot tiles with a handful of toggles each.

What I've checked:

• PCI resource allocation in Windows: the root port feeding the GPU (Bus 3, Dev 1, Fn 0, "PCI Express Downstream Switch Port", VEN_8086&DEV_4FA4) only gets an ~18MB memory window from firmware. Not enough for even a default-size VRAM BAR. So this is firmware not reserving address space, not a driver/OS issue.
  
• Pulled P12RGG.CAP out of the Samsung update package (tavinus/SamsungBIOSTools method). Delivered as a Windows firmware-class driver (WFU_PRGG.inf, FirmwareId {6B55D383-7F30-4605-9BC6-6685A32C0AC5}), labeled "SAMSUNG ELECTRONICS System Firmware".
  
• No string for "4G Decoding", "Above 4G", "Resizable BAR", "ReBAR", "MMIO", "Resource Padding" anywhere in the file. ASCII or UTF-16, compressed or not.
  
• Only one compression scheme in the whole image: LZMAF86 (GUID EE4E5898-3914-4259-9D6E-DC7BD79403CF), 38 sections. Recursively decompressed all of them, including ones nested two levels deep - 83 blobs, ~62MB decompressed. Still nothing.
  
• Searched for strings I can see live on the actual Setup screen right now (Secure Boot Control, Purchased Date, USB Charging, BT Audio Offload). Also not found, anywhere, in any encoding. Tried brute-forcing single-byte XOR and basic add/sub/rotate/reverse against known plaintext too, no hits. So either Samsung's skin pulls its text from somewhere outside this capsule, or it's obfuscated in a way I haven't guessed yet.
  
• The "AMITSE" string only shows up inside NVAR entries (AmiTseSetupGuid) - that's stored variable data, not the actual Setup Utility driver/IFR forms.
  

So text search is a dead end, both for the skin and for the option I actually want. Looking for anyone who recognizes this format/obfuscation, has Alder Lake reference source to cross-reference the SaSetup/PchSetup Above4GDecoding field offset, or can just add the question back via IFR - the underlying variable is probably still there even with the form ripped out.

CAP attached (compressed, otherwise I blow the 20MB quota). Can pull any other section out of it on request.

Thanks for any help! It's the first time I try this so please bear with me.