Steve Dower, thanks for looking at this.

After reading the thread from my amature point of view I kind of liked suggestion of Daniel Lenski to replace the binary delete argument of the current NamedTemporaryFile implementation with finer-grained options https://bugs.python.org/issue14243#msg164369

This would also take care of the comment from Dave Abrahams, that 

<<Even if Windows allows a file to be opened for reading (in some circumstances) when it is already open for writing, it isn't hard to imagine that Python might someday have to support an OS that didn't allow it under any circumstances.  It is also a bit perverse to have to keep the file open for writing after you're definitively done writing it, just to prevent it from being deleted prematurely.>> https://bugs.python.org/issue14243#msg155457

As for your comment to include FILE_SHARE_DELETE. If the decision is taken to go this path, shall we also not include FILE_SHARE_READ and FILE_SHARE_WRITE?
https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea