Sorry for really late response (and please delete this comment if it does not meet the standard of this subreddit).

Can you by chance read Japanese (or Chinese)?

Japanese-Ming trade from the 14th to 16th centuries (especially the later) has recently much attention from Asian historians, maritime archaeologists (Shinan Ship Wrecks from the early 14th century) alike, even some study handbooks has been published.
I recommend to make use of google with some of their favorite key words like 'Maritime Asia' or 'Maritime History Eastern Asia'.

If you can find some translations of the following books/ scholars works in English, it would be very helpful for your study, I suppose:

• HANEDA, Masashi & OKA Mihoko (eds.). A Maritime History of East Asia. Kyoto: Kyoto Univ. P, 2019: Has Just published in English translation (Here is the publisher's site of Japanese Original). While unfortunately the first part largely end in ca. 1350, this book (a kind of textbook with the further readings) is written in the first-line Japanese scholars on the trade and other networks across the maritime Eastern and SE Asia, so definitely recommended if you are interested in Japanese history.
• MURAI, Shosuke et al. (eds.). The Introduction to the History of Japanese-Ming Relationship (日明関係史研究入門). Tokyo: Bensei Shuppan, 2015 (in Japanese): is the latest introduction of your topic, unfortunately only available in Japanese.
• YAMAUCHI, Shinji. 'New Trends on Asian Studies: The Research Group of Maritime Asian History'. Journal of Cultural Interaction in East Asia 5 (2014): 123-126 (in English): The author himself is specialized in Japanese-Song trade, though.

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• MUKAI, Masaki. 'Contacts between Empires and Entrepots and the Role of Supra-Regional Network: Song-Yuan-Ming Transition of the Maritime Asia, 960-1405'. In: Empires, Systems, and Maritime Networks Working Paper Series 01 (Osaka University), pp.1-24: While Mukai is specialized in the maritime trade of Yuan China, he uploads his paper with some of comments as well as other papers from this interesting working paper. (in English).
• I really hope that I could find any work of Yu Hashimoto (Hokkaido Univ.) available in English. While he is actually rather specialized in 15th and 16th century, his study of 'imposter' envoy delegated from some warlords (not Muromachi shogun) to Korea and China is very interesting. He also uploads an image of reconstructed license for Japanese-Ming trade (I assume you know the license system during the reign of Yoshimitsu Ashikaga).
• As for Japanese-Ming relation under the reign of Yongle Emperor, the following Japanese (sorry) paper by Yoshiaki NAKAJIMA provides the good overview of the historiography in Japanese as well as both Japanese and Chinese primary sources: NAKAJIMA, Yoshiaki. 'Japanese-Ming "tribute" trade under the reign of Yongle Emperor'. Shien 140 (2003): 51-99. (in Japanese only) https://doi.org/10.15017/1149

[Edited]: corrects some links.