Actually, I'm not 100% sure now after all. The way these work by modifying and resaving the map file would mean a different, new source file for the replay. It would have to be saved in the cache folders, and launched from there, and left behind with a unique name I suspect.
Oh well, just trying to help. I'll watch the progress...
EDIT: The problem is, these launchers take the map, and recompile it with the AI changes and AI players added in, and then saves it somewhere, and launches it from there with Lazy Launch.
If it creates that temporary map file in the cache folders, it would work for replays. However, you'd need to have unique filenames each time to avoid overwriting previous maps. This would mean that you're cache folder would quickly start to swell with new maps, at 1-2mb a piece, with each game. So I'm not sure if there is a practical solution.
(sorry for double posting this in the two different launcher threads, trying to help solve this problem, if possible, and both launchers are nearly perfect, in except for their ability to play replays)