T480 - Colour banding?

Hi all,

I’m trying to install Monterey on a Thinkpad T480, but I’m having an issue with colour banding. When I installed Big Sur last year, there was a solution mentioned (a custom version of WhateverGreen and an edit to GPU properties in config.plist). Implementing the same solution leads to a failed boot on Monterey.

The working Big Sur EFI is this one, and the one I’m currently trying to use is this one.

Any pointers would be appreciated. Thanks very much in advance!