I was looking at the info for the 4.6 beta version and saw this:
Improve revoked UEFI bootloaders check to support Linux SBAT, Windows SVN and cert DBX
I have a secure boot system with "The update that killed Ventoy" and this line interested me, so I tried the beta.
Bookwormpup64 ... kinda works. It pops up the grub menu, but the borders are garbage, it can't find the kernel, and I get a "shim error" message. It does kinda work though and it didn't work at all before. Getting closer to a native-boot Puppy.