After using the N64 NSO on my emuNAND (atmosphere) with CaVE DBM, I got the expansion pack sub on my legal sysNAND. Uninstalled 64 NSO from emuNAND (SD card), booted on sysNAND and installed all three GB, GBA and N64 NSOs.
Turns out, the first two work perfectly fine. N64 can't boot, directly...