from what I read, the DRM simply checks the save RAM size. if melonDS detects the size properly (or is given an existing save file with the right size), it will properly redirect out-of-bounds accesses to the save memory.

most of those anti-piracy measures are aimed at bootleg carts, copiers or flashcarts that try to accomodate for most games by having SRAM as large as possible. an emulator that properly detects and enforces the SRAM size will not be affected by those measures.

there have been games that used tricks explicitly meant to break emulators. often features that emulators choose to ignore because they're too much effort and processing power for very little gain. a prime example would be those Wii games that basically overwrite critical memory with garbage, then invalidate the data cache: on the console, the data stays entirely in the cache and doesn't make it to memory before the cache is invalidated. a sane emulator will ignore the cache, resulting in memory getting trashed.

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Kuribo64