Default [Q] Downgrade MF3 to MDL?

Hey all. I have an at&t GS4 running MF3. I remember when MF3 first came about how everyone was saying it will be impossible to downgrade this firmware. My question is has someone figured out a way to do it yet? I don't understand why this "qfuse?" would stop us from downgrading our devices. My main goal with a downgrade is to be able to install GPE KitKat. I currently have safestrap but i believe it is still limited by not being able to use roms that are not 4.2.2. Hope to get some help soon. Please don't be rude and thank you for your help.

Oh! Also if there is another way to run GPE KitKat on MF3 please let me know! Maybe safestrap can do that now! idk.

Again thanks for all the help.