Having a standard console window can indeed be useful, especially for sending text easily.
While I'm not familiar with the specific requirements of MusicBee, in C#, you can use the AllocConsole function from the kernel32.dll library to create a new console window. Alternatively, you can redirect the standard input/output using the Console class in C# to achieve similar functionality.
If you're still looking for more guidance or examples, https://www.zaptest.com/grey-box-testing-what-is-it-types-process-tools
might have some helpful resources. They provide insights into grey box testing, which could potentially offer some valuable information related to your question.
I hope this helps, and best of luck with your MusicBee plugin development!