You can't really develop a kernel-mode driver nowadays without being an incredibly large OEM. Otherwise, you won't be accepted by any anti-cheat.
Getting your driver signed seems like a pain these days, yeah
Also got a BSOD in vgk.sys, and it left a bunch of junk in my EFI partition after I uninstalled it. Fun times.
I’m sure there are more open source examples. A newer one is https://github.com/namazso/PawnIO/tree/master I guess?