The escaping was mostly already in the initial regex, that I didn't write, so I left it as-is.
For what it's worth, `Regex.Escape("// #region")` returns `//\ \#region`. But I agree that in my testing it worked without escaping (better safe than sorry, I suppose).

Regarding spacing, I have only amended the regex to match the folding mechanism. There is not point in allowing more spaces here because you won't be able to collapse the region. It is a different piece of code that takes care of the outlining and as far I as understand, it is not based on this regex. Of course it could be updated too but it wasn't the point of this change.