I understand your points but you cannot make everyone happy and have to choose your audience. I also plan to include dsp topics, but geared towards beatmakers and musicians and not just the math oriented folks. The appreciation of complex topics simplified but not dumbified will attract new readers and will sustain the more erudite ones from the community. FFT was pioneered in the 17th century, but most musicians probably won’t know or care to know what is its use in the very devices we use everyday. It is just one example. The text has to be well presented and made intuitive, book reader or not : learning new knowledge for themselves is always a rewarding experience. Ideally this would be a book I would have given myself years ago when music was an all encompassing affair for a young and keen college student. If you have read Gareth Loys Musimatics books for instance you would understand why books like that are so important for posterity. My goals are far more tempered but with focus.
Japanese Renoise books are already available.
Japan has always been an eclectic, pioneering and a dedicated community. She is also the world’s second largest music industry 
They have established a Japanese hip hop scene for decades now (Budamunk, Yotaro, DJ Krush, Dj Kentaro and others). It is the best market for such niches given that Renoise has its own Japanese forum, I am not surprised at all. We do need one in English though and cover a compendium of topics that go a bit further and also incorporate academic music frameworks as well as provide dsp explanations so that the next beat maker can be well equipped to enjoy their very own sounds, signal processors and generators and sample manglers while gaining a foundation they can build on and keeping Renoise as the primary hub for such excursions. Given the recent rise of tracker oriented hardware development, demand exists without a doubt.
Also, I am looking to connect Csound with Renoise in everyway I can. I might end up with a Renoise tool eventually as a result of my experiments. Csound works in Emacs (which I use a lot, M-x csound-mode), Vim and Vscode. As a shell command, it can be scripted extensively. It has an API, it does REPL live coding via udp protocol and the API, and it uses OSC as well. So given the options it’s not a difficult thing to come up with if one is comfortable enough with Lua and some commitment to a dev schedule. If I can use csound scripts inside Renoise with Renoise’s sequenceing powerhouse, it’s all I would need for the end of times, the perfect partnership.
Book chapters will also introduce Csound and how it can readily used to build your own sampler, bass synth, granular synthesizer, FM etc and essentially a hip hop beatmakers regular arsenal. Then there are aspects of key grouping and midi real-time performance to be succinctly covered along with use of midi channels and controller opcodes. Renoise will be presented as a beatmakers tool along with a host of diagrams and mindmaps to make the interface appealing to newer users. BTW the Csound score syntax is very much a per note per line entry exactly like we are used to in trackers. It does have a parameter list array for each note in order to control the instrument it is destined for. It is like music assembly programming not unlike hardware synth patch cables. So it covers the analog base as well in terms of explanations and examples.
Because this method of note entry is native to both Renoise and Csound, it’s perfect opportunity to combine both as they are complimentary.
Then there is the thing about writing style and good editing, publisher branding, page count, projected sales figures etc. I expect diverse musical communities to benefit from this synthesis of either niches, one cultural and the other academic. The Csound user manual and plethora of resources do explain a lot, just like Renoise resources does for its own, however, I am yet to find a singular resource that provides a presentation that the everyday beat maker would be able to use with great efficiency so should they choose to do so. When it comes to crunching manuals they are not the best crowd known for attention span on printed text. Therefore, a well prepared manuscript is well in order for a more cerebral beat maker or the ‘instant coffee’ type too. Additionally this text can potentially fasttrack someone looking for a university course in such topics.
My question to all of you, as Renoise users what topics would you like to be covered? Compiling this is an important part of the preparation process !