The only difference between master and legacy is the inclusion of Rosalina. There's absolutely no reason legacy should be able to launch and emunand and master cannot.
This seems even weirder - EmuNAND size has absolutely nothing to do with how it boots. A full-size EmuNAND is the exact same as a minimum size EmuNAND - the only difference is the minimum size one has a large amount of unused, unpartitioned space. There is absolutely no reason this should affect an EmuNAND boot.
That being said, I've brought your issue to AW and Tux. AW has a 9.2 EmuNAND we can test on so I'll let you know if your problem is user error or reproducible soon enough.
EDIT: What console model do you have?
This is known and we cannot do anything about it. Those games depend on oddities in how the *hax environment is set up, and replicating that environment without going through the same process (ROP, etc.) is extremely difficult. Those games will probably always require *hax, unfortunately.
It's definitely strange, but for whatever reason, it does crash. O3DS and N3DS. I'm not sure why. I usually do install Menuhax to mine for the convenience of going straight into the boot menu. But minimum sized EmuNANDs should break too if that was it. Adding to the strangeness, on the N3DS, Cakes cannot load a 9.2 either (for that matter, it can't decrypt TWL firmware, but I suppose that's a topic for mid-kid's thread), though Puma can, but even that requires a decrypted 9.0 firmware.bin for some reason.
I think most, if not all, of those issues are solvable by simply rebuilding those games with latest ctrulib.
Well, I'll try that since I recently updated my devkitpro then. Though I think some of these are not open source. I'll see what I can get working, and upload them for those who can't compile things. Thanks for the suggested fix. Though I'm even more curious to hear something back about the whole 9.2 thing. I suppose it's nothing to keep Legacy in development for, especially since I already have a workaround, but it's just baffling all the same.