I do have smaller MemCards but there are thousands of miles away [impossible to get thanks to Corona ]well unstable means if you toogle too many settings things might break since the bigger the memroy card bigger the memory it takes away from nintendont, but you shouldnt worry only the real 16mb option is the most unstable one that even breaks disc swap, 1019 should work fine.
Let´s say i also put a smaller backup in the "saves" folder one day... is that possible? I.e. two different backups.
And my final question: Specific game files (e.g. F-ZeroGX) cannot be moved between physical MemCards. How would sb then create a unified backup? It seems one would have to keep all of them separate.