These Secret INI settings should be in XMPlay.ini that comes with the program (but they can be commented out). Would save some time for new users to have to find the settings on the internet and add them manually.
Adding all the secret settings with default value is suggested in the Illustrated Manual Section 6.2 - Secret INI settings
for experienced users:
Put them all there:
Some of the cutting edge users intentionally put all of the "secret" settings (each with the default value) into the xmplay.ini file even if they don't intend to modify the setting. If they want to experiment later, they can see the setting's correctly-spelled name and change from the default value on that line.
Some of the settings are common enough where placement in the default ini might be a good idea (SingleClickTray comes to mind), but many are so obscure that you'd have to know what you were doing to even mess with it (hence the "cutting edge users" and "experiment" comments).
Even so, it has been some time since someone asked if they could configure the tray icon clicking performance. That tells me that the information we are currently providing (and the methodology) is working.