Bypassing Apple's chunklist checks (High Sierra)

Hi all,

Apologies if this is in the wrong sub as I'm installing on a MacMini - but I figured this community might know the answer.

I have a ebay-purchased MacMini5,2, the one with the Radeon GPU, but the GPU is faulty and the system won't boot (or rather, it might, but I get a blank screen). If I remove the AMD* kexts from the BaseSystem.dmg in the High Sierra installer, it boots and is usable, but the installer won't install, because the verification of the image fails because I removed the kexts.

Is there a way to bypass the image check using one of the various bootloaders or OCLP? I'm happy to dive in deep into stuff, so if anyone knows if this is possible, let me know.

I might try just renaming the files, but I don't think that'll work.

Any and all help appreciated!