As shown, many developers include manuals, DC Designs does (2), PMDG does (2) one flight training and one setup manual.
You have joined the choir, every single person on this sim has begged for manuals on settings, setup, performance curves in depth, and asobo gives us nothing, why, they made deals with all the YouTube channels who would promote this sim and those folks make a bunch of money doing videos. That is why I fly in X-Plane more lately than here, manuals, about 117 pages of one, and XP can be installed on Linux, which I might go to because of the audio problems windows has increasing the volume on anything playing to 50% without warning, blowing out my ears every single time. I have searched for solution and not one thing suggested works. It’s got to be imbedded in the OS, and I have just about had it with MSFT for those. It’s not support is a money train.