I am using a program called 3ds Lazy 1.2 to make my CIA. it has a make 3ds rom option it builds but doesn't let me run it on the gateway card so i have to make a CIA. and basically if the CIA doesn't save it means there was something wrong with the edit. i ahve the xors saved on my SD card so i don't have to generate them everytime i want to decrypt and try. but it usually takes 3-5 minutes to decrypt if i close the program and then 3-5 minutes to make the CIA.
Installing the CIA takes about 15 minutes.
and i am installing and playing it on my 3ds.