This time you are very near....
Both the wrong and the correct help create a new console window and write there the help text. The wrong one stops the text in the middle and produces the little warning window. I click OK and the remained text is written and a "click to close" little window appears just over the second created console. If I click on it, the second console closes.
Both if XEP128 is launched from the console or from Windows, it produces a brief second console, this time with text, but it is too fast to read something. When it closes, the emulator starts normal.
I'm not sure if I understand fully, but maybe that's the expected behaviour you've described ...
Xep128 normally (now, I mean) tries to open a console whatever option you've used. If help is not requested, it will close on start of the emulation, so you'll see a console appearing and disappearing within a moment. If you want the console window to stay, you need to use the (new) "-conwin 1" switch. In this case, the console should remain during the emulation as well.
About the help: indeed, if you try '/?' it will warn you, and you can see only the part of the output, till you click OK on the warning dialog.
The important thing: if console was open (regardless because of help or -conwin 1 mode during the emulation) and Xep128 tries to exit, it should warn you to "click to close", this policy is introduced to be able to read the content of the console. Currently, Xep128 always tries to open a new console, it won't use the parent's one (ie: started from cmd window, which is already a console ...), since it's problematic to "mix" output of two programs into one console (because cmd.exe will continue to run, so output of both programs within the same console would be well "strange" and also makes impossible to future use of console - ie to able to input from there, with implementing some monitor-like program). Also, it seems it would be problematic to use the parent's console, if it's administrator privileged etc. I think it's a more clean way to always use an own console, and also it's consistent behaviour at least!