There are a few bits of scripting that I understand and you'll need to grasp to edit it. First is that the "cheat" that is activated by button press (for a short while before turning back off) is: a function (a list of commands) that is called (seeked out and activated) by the mod when you press the button associated with it. You'll have to look at how the lines of commands are organized to find the autoheal function. Next realize that "commenting out" is done by putting a # sign in front of the line of code. Commenting out means you are telling the mod to ignore that line totally, but leaving it in just in case you want to re-enable that line or you are actually just leaving a comment for reference. You can find a few comments in the file already.
SO: find the autoheal function, comment out what you don't want it to do. For me, I put a # in front of every line except the one about STA which would be for stamina. Of course don't comment out the beginning or the end of the function, just the inner commands that you don't want to happen. Hope this helps get you on your way!