Just going to put this here for people to read as a sort of reminder. Since I anticipate that there's going to be some funky comments in the future about the MIG Switch in its current state and the Nintendo Switch 2. So don't take this as a targeted comment(s).
You need to understand the difference between your standard flash cartridge running custom ROM loader and general management software, versus a cartridge emulator. Both are flash devices, but both are drastically and functionally different from each other. One is intended to bypass security measures for the sake of running custom software (ROM loading is merely a collateral possibility due to bypassing security and such), while the other is intended to run legitimately, validly, signed software (which happens to solely be the video games we launch on these systems) natively without bypassing any security execution measures. Based on my understanding, the only reason the MIG Switch even worked without requiring all of the necessary assets for a game dump, when running on a Nintendo Switch, is due to the fact the security system doesn't stop you from running software despite having invalid or insufficient information outside of the ROM image itself. The ROM itself is valid and legitimate to pass the measures, everything else is supposed to be extra layers of checks and balances on top of that, which I believe the system does in fact detect, valid or not, missing or not. The system security was never designed to halt all operations if anything else is invalid or missing, merely because normally that never actually occurs in the first place with game cartridges (they all contain the necessary valid assets). If the ROM image itself was damaged or modified in a way that renders it invalid, then the security measures would step in because now it's not valid software being detected anymore, so you won't even see it show up let alone run it. Sure, anyone could blame Nintendo for not having the foresight to check absolutely everything and put checks and balances to halt execution operations, but quite frankly they shouldn't have to either, considering the point of the MIG Switch wasn't even for piracy to begin with. That's also why you don't see a flash cartridge with a ROM loader and general management software, kin to the Nintendo DS era of flash cartridges, this would require the security measures to be bypassed. You also don't see homebrew running through the MIG Switch because all homebrew software created for the Switch avoids being valid by the security measures, they would have to be created with tools only Nintendo has access to, which is already a huge legal issue of its own.
The fact that as of this time of typing, the MIG Switch cartridge doesn't work with the Nintendo Switch 2, as stated in a previous comment I made in this thread, could be happening for a number of reasons, we can only guess. We still don't know if the tests being done are with full proper dumps or just partial dumps, for all we know everyone testing so far is using pirated ROM dumps or something, nobody has made it explicitly clear yet. I wouldn't consider this a huge loss though for anyone who runs their games legitimately with their own dumps, just use your official cartridges for a while. As for the pirates, well, sucks to be you I guess, not sure what to tell you, guess you'll be stuck sitting on systems for a while.