The dependency on a particular set of file extensions to "enable" the panel is too limiting.

Given the nature of a tool like Notepad++, there are times when I just want to open it and start taking notes (e.g. for a meeting, or to-do items for the day, or ...). Markdown in Notepad++ is a perfect way to take those notes; I can use bullets, bold things, etc. The panel, however, will tell me that "The current file new 1 has no valid Markdown file extension."

If I have to save the file, to force a MD-friendly extension onto it, then I'm not going to be using Markdown++ in the first place, I'll use Word or Google Docs.