@naquaada
macOS Monterey disables GCN 1.0 support via policy, even if the ID is present. Some IDs (like 0x682B) remain in the plist for historical reasons or internal backwards compatibility, but: AMDRadeonX4000.kext drivers are not loaded. Even if the kext is present, matching fails at runtime. This also applies to 7000Controller.kext, which does not contain Oland-compatible framebuffers, so even if it "sees" the ID, it is of no use.
Great point! Yes, it's true: the ID 0x682B (i.e. your RX 250) is present in both: AMDRadeonX4000.kext ➜ legacy GCN 1.0 drivers (Oland, Cape Verde) AMDRadeonX5000.kext / X7000Controller.kext - used for newer models, but sometimes with leftover support - But be careful: being listed in kexts does not mean they are actually loaded!
Check with gpuid if your card has Uefi support or if it needs to be flashed, try my config.plist, I put a more compatible framebuffer in the devices proprierties "Futomaki", but you can also try Hamachi, remove the no_comact_check from the boot arg and still keep your config working
configOlandXT.plist.zip