Looks like I no longer have the code I used to make test data, but because it generated the minimum amount required to test the features implemented at the time, I think it would not be much help with PE files. Yes, implementing mspatchc may allow proper testing, and it wouldn't need to have especially fast or high-ratio compression, but even then it's not trivial to do. I have my hands full at the moment, but I may look at doing this later if nobody else has.