Cheats and Wifi on MelonDS core not working?

Is it possible to use cheats on MelonDS? If not, how would one go about translating, for example, widescreen patches to perhaps Retroarch’s cheat handler? Assuming it can be used as a workaround. Desmume performance is much worse. Also, apparently MelonDS stock supports Wifi. Was it removed from the core?

It appears to support cheats through RetroArch’s cheat system, based on the core documentation:

The wifi support isn’t removed, it’s just not exposed via the libretro core currently. Maybe someday.

I’m doing something wrong. The cheat for widescreen in Mario Kart DS (source), for this example, is:

520775D0 00001555
020775D0 00001C72
D2000000 00000000

I don’t know almost anything, but it is my understanding that the actual address is 000775D0. I don’t know why the creator changed it to start with 52 or what the additional lines translate to in English, but that 52 change requires a 32-bit search, which yields unrecognizable addresses, and retroarch crashes with that. Changing the recognized address’s value found on a 16-bit search from 1555 to anything else changes nothing. Cheat in Desmume:

Address found under MelonDS:

Crashing on a 32-bit search: