Worth mentioning that a spelling reform like Twain's would mean that every accent would need to be spelled differently, or the sounds wouldn't match for most speakers. It's quite possible that some British dialects would be very hard to read for some Americans and vice versa, even if they were used to the system for their own dialect.

For instance, Twain spells "after" like "aafte", but in my accent I would probably spell it "afdr".

Twain has also run in to the problem that spoken English has far more vowels then written English does. He uses "ai" in both "minds"/"maindz" and "replace"/"riplais", but presumably they represent different sounds.

Presumably OP's system has the same problems with the dialects of Chinese, now that I think about it. Although I know very little about Chinese unfortunately (only what I know now from a few seconds of googling).