It's not just the thread pitch that's not standard. The Paragon dropouts all have an unthreaded recess on the threaded side, to allow for the dummy axle to fit, but some of the other manufacturers don't do this. This means you have to spend some time modifying the dropout or modifying your dummy axle to fit the minor diameter of the thread. I make my own dummy axles and I have 3 different ones for 12mm x 142. One with both ends at 12mm, one with a 12mm end and a smaller end to match the minor diameter of the M12 thread and one to fit Syntace dropouts.