I updated the CF-Auto-Root file for the I9505
(link has stayed the same, see first post), including the new SuperSU. This should just work without any strange workarounds (like Supercurio's StupidSU, or deleting KNOX, or whatnot). At least, it seems to work for me, and I'm on stock MDN firmware (including stock kernel and recovery). I have not seen any SELinux/SEAndroid popups or any of that yet.
I imagine if you have used any of the other fixes, you may still experience issues with this new CF-Auto-Root unless you flash back the correct stock kernel (if you've changed it) and/or system partition (apply CFAR *afterwards*).
Let me know if there's any issues. I've had the SGS4 for a few weeks, but I've gone on vacation as soon as I got it, and only started playing with it yesterday, so I may have overlooked something.
Please don't announce this anywhere else, I'm waiting for the I9500
version to be working properly before announcing it everywhere