XMP.exe was updated last in July 2016, so it missed out all further updates from v1.0.23 onwards. And LibXMP was updated last in October 2016, missing all further updates from v1.0.24 onwards.
Perhaps you can provide two sets of XMP.exe and LibXMP? One set of XMP.exe and LibXMP updated to the previous v1.0.25, and the other set updated to current v1.0.26. This way we have the freedom to choose, without maneuvering into a dead end due to the experimental nature of the current update.
Btw, I overhauled the file Formats.txt a little to improve the readability. I send you a PM, please feel free to use it or not as you see fit.