The fake/clones choose to fake the R4 brand because it's the one that's well known.
It's the exact same thing as people calling all vacuum cleaners "Hoovers", all cotton swabs "Q-tips," or all tissues "Kleenex", everyone calls flashcarts an "R4", mostly out of not knowing other flashcart brands exist.
Also yes, flashcarts cannot access any DSi functions, or any IR functions. Flashcarts will always run a DSi-enhanced rom in DS mode, even on a DSi system. Obviously with no IR sensor on flashcarts, you'll have no IR functions, something you can live without on the pokémon games thankfully.
It's the exact same thing as people calling all vacuum cleaners "Hoovers", all cotton swabs "Q-tips," or all tissues "Kleenex", everyone calls flashcarts an "R4", mostly out of not knowing other flashcart brands exist.
Also yes, flashcarts cannot access any DSi functions, or any IR functions. Flashcarts will always run a DSi-enhanced rom in DS mode, even on a DSi system. Obviously with no IR sensor on flashcarts, you'll have no IR functions, something you can live without on the pokémon games thankfully.