What's kinda neat about musl libc is that the interpreter/runtime linker and libc.so are the same executable, so that if you just dynamically link to libc, it does not need to open ld.so cache or locate and load libc.so.
More importantly this uses the devkitPro/libnx homebrew toolchain, while the OP project uses the official SDK (the "complicated legal reasons" behind the absence of code probably being an NDA signature).