Please dont post unless you're going to further the thread...
On that note, removing r6t3 or bridging u6t1 or u6t2 (version dependent) prevents efuses from being 'burnt'. This will result in an error during the update (iirc), which you can then recover by restoring your nand from a backed-up image. So, it doesn't "prevent" but rather allows you to recover from an accidental update.
Caster.