Chris Main wrote to you:

   However, if you do choose to release your software under GPL or LGPL you also
   place yourself under an obligation to provide build instructions. This is not
   what I say, it is what the GPL/LGPL themselves say.

This is wrong. Section 4 of the compliance guide, from which Mr. Main proceeds to quote, is directed towards those distributing GPL software written by other people. The GPL does not place any such constraints on the author(s). If you want to distribute Windows binaries, and don't want to bother explaining how to build nxlog on Windows, you are completely within your rights. If Mr. Main cannot figure out how to build it on Windows, he is simply unable to distribute a modified version that runs on Windows (since the GPL would require him to explain how he did so), and you are not obliged to lift a finger about that.