During my time researching Shenmue II by d3t, I come across some unused debug code which I have recreated.
The debug logger is all AM2 debug, whereas the majority of the rest seems to be d3t-specific.
To use, unzip d3tDebugEnabler.zip into your Shenmue2 install folder and open the game as normal.
F12 will toggle all windows on/off.
To remove, delete d3tDebugEnabler.asi and winmm.dll (and optionally imgui.ini) from your Shenmue2 install folder.