Got random reboots with the SM-907A (xxxxAND7) via towelroot method. Used the latest SU and just let it disable Knox on it's own. The more knox stuff I froze via Titanium Backup, the more frequent the reboots were. Root itself did work though; knox still 0x0, showed as "official," but the random reboots were a bit annoying. Even letting SU disable Knox and leaving everything else enabled, still would reboot to the AT&T logo every couple days.
I've already uninstalled the AT&T bloat and left everything else there. I'm just going to unroot for a bit and see how it goes. Besides, not like disabling all of that stuff really helped performance much anyways. AdBlock randomly caused webpages not to load and I don't keep anything all that important that needs to be backed up. So I'll live with near-stock + Nova for now.