AX 2012 R2 setup broken by win10 20H2

It appears as though having updated Windows 10 to 20H2, the AX 2012 R2 setup.exe returns the "smartscreen" "This app can't run on your PC".

This could quickly become a problem for us as most my 100 users use the fat client! AX still runs on machines that have updated to 20H2.

This worked when on windows 10's 1909 version fine. I have disabled SmartScreen's features, but still receive this error.

I actually ran up the R3 setup.exe and that launches fine.

Converting everyone to use remoteapp is currently my only option, but is going to cost me a bunch in RDS licensing and will be painful.

Needless to say, we have embarked on that D365 road, but any solutions/suggestions that can be provided for the interim would be appreciated.