You might be able to install latest macOS using OpenCore-Patcher (it's just bootloader IIRC it does not modify the OS itself in anyway so it should be pretty safe). I've used it on 2011ish 17" mbp and had no issues.
Thanks, I'll take a look at that. Next thing I was going to try was host a VM under Linux and see if I could make a "hackintosh" on real Apple hardware.