Here you go windows users - this is a small test program made in c# (so you'll need net framework installed on your computer if you don't already have it) for creating Atmosphere Loader IPS patches. I just knocked it together today quickly and will post the code up on github when I make a nice gui + add the ES/FW stuff, maybe even I'll add a few extra things while I'm at it - in the meantime you can test it if you want, no need for python to be installed with this and no need for key files as you don't need those for the Atmosphere loader, so nothing illegal is in this program. GUI is crappy just now, obviously I'll make it nicer once the code is all done.
To use - open the program, drag your package3 file onto it - the Atmosphere loader IPS patch will be made automatically if everything went to plan.