The supported way is to use the Kernel Debug Kit and use two Macs. See https://developer.apple.com/documentation/apple-silicon/debu....

I guess you could also write a kernel extension that allows inspecting memory, changing memory, setting breakpoints, etc. from a user-mode program using fcntl but if you stop the kernel, chances are user-mode locks up, too (might be guaranteed; I don’t know how much multi-threading there is in the MacOS kernel)