Situation on trip the Knox or not: (No idea on downgrade as I never try, I think it won't under same bootloader version)
- Flash any stock ROM including Kitkat officially or not with odin without rooting - won't trip knox.
- Officially phone came with MJ1 or older - root with URDLV won't trip knox.
- Officially phone came with MJ7 or later - root with any method will trip knox.
- Officially phone came with MJ1 but later updates to MJ7 with OTA/KIES/PC Odin and later - root with any method will trip knox.
- Officially at MJ1 and rooted and update to any firmware excluding KitKat ROM using Mobile Odin Pro only - root will remain and won't trip the knox.
- Install any custom recovery and custom kernel will trip the knox.
Update KitKat via Mobile Odin Pro (MOP) without trip the Knox:
- Your current bootloader is not newer than MJ1.
- Load Official Poland ROM in MOP
- Enable EverRoot, Choose option "Download mode" in after flashing. Start flashing.
- After booted into Download Mode, connect your phone to your computer and run PC Odin 3.09.
- Load this bootloader http://forum.xda-developers.com/show...&postcount=352 in the BL section
- Check Phone Bootloader Update and F.Reset.time, un-check Auto Reboot and Start Flashing.
- When Odin says RESET!, switch off your phone and reboot normally.
Phone: HTC ONE (M8) | | Kernel: Stock | ROM: ViperOneM8 v1.8.0 - 4.4.2 KitKat
Future Phone: ~ nil
Ex. Phone: Nokia 3310, Samsung S500, Nokia 7610, 7270, 7280, SE K750, Nokia N73, LG Viewty KU990, Samsung Pixon, UltraTOUCH, OMNIA II, Nokia 3120 Classic, Google Nexus One, Samsung Galaxy S II, S III, Sony Xperia Z, Z Ultra, Samsung Galaxy Note 3.
Tablet: Sony Xperia Tablet Z | ROM: Stock v10.5.A.0.230 - 4.4.2 KitKat
Future Tablet: Still Finding
Ex. Tablet: Google Nexus 10