Linux - with Microsoft's permission?

https://www.omglinux.com/boot-linux-modern-lenovo-thinkpads-bios-setting/

The newest Lenovo laptops come with Microsoft's "third-party" key disabled. It is not very hard to enable it, but between Microsoft and the laptop makers, that option needs to be set to the disabled state. Perhaps someday the requirement for Microsoft's blessing will be that the key is disabled (or removed) and not enableable.

How hard is it to add my own key so I don't need Microsoft's permission to run a non-Microsoft OS on my laptop? (assuming I want the protection of secure boot, or the laptop will allow me to disable that.

Would I need to re-sign the kernel on every update where the kernel is replaced?

Would I need to sign a kernel I compiled locally? And after all, isn't being able to configure and re-compile a custom kernel one of the differentiating features of Linux?

Do other executables also need to be signed?

Edit- - Sure there are parts of Microsoft that <heart> Linux, but there are also parts that do not. Microsoft is a large enough company that there is room for both.