Patching in your own kernel signing certificate

[Kerlingen]

I attached a kernel debugger to my VM and tried to load the driver with devcon

This is already the first mistake made in the article: As soon as a kernel debugger is attached, many of the kernel protection features are automatically disabled, including the kernel signature verification. Drivers do not even need a test signed certificate in this case, they will load even without any signature.

manually added my root certificate to the trusted roots store the normal way

This is also total nonsense. The root certificates for kernel signing are hard-coded in the executable files, they are never read from the trusted roots store. The whole article seems to focus on removing certificate warnings in the GUI, a part which has absolutely nothing to do with the decision if a kernel driver is permitted to load or not.