Were there any attempts to alphabetize Chinese that did not involve writing systems existing in other languages already? This would be something like a Chinese analogue to the development of the Korean writing system.
Pinyin, Wade-Giles, Gwoyeu Romatzyh, and Bopomofo were all developed in the modern period, and are all examples of romanization specifically, so I'm not considering these.
I would also be interested in learning more about phoneticization via the influence of non-romance languages too. For example, Wikipedia mentions that Chinese itself became more phonetic when Chinese linguists started to recognize "initial" and "final" sounds while transliterating Buddhist mantras originally written in Sanskrit.