That's about it. I'm interested in reading about this particular topic, but I can't seem to find any books or articles about it in english. I'm not opposed to learning chinese and/or japanese if necessary, but that's not particularly ideal right now. So, that.
Thank you to anyone kind enough to answer.
Chinese piracy:
Robert J. Antony, Like Froth Floating on the Sea: The World of Pirates and Seafarers in Late Imperial South China, Institute of East Asian Studies, University of California, Berkeley, 2003. Excellent book, in-print, and cheap. https://ieas.directfrompublisher.com/catalog/book/froth-floating-sea
Two other possibilities, which I haven't read:
Antony, R. J., ed. Elusive Pirates, Pervasive Smugglers: Violence and Clandestine Trade in the Greater China Seas. Hong Kong: Hong Kong University Press, 2010.
Murray, D. Pirates of the South China Coast, 1790–1810. Stanford, CA: Stanford University Press, 1987. Out of print, but you might find it in a local university library.
South-East Asian piracy:
Y.H. Teddy Sim (ed), Piracy and surreptitious activities in the Malay Archipelago and adjacent seas, 1600-1840, Springer, Singapore, 2014. Includes 2 chapters on Portuguese and Spanish pirates in the region. Superbly referenced, and will supply you with plenty of leads for more reading on the topic.