Yes I guarantee that you can downgrade from Official OTA to RC29. Like I said I did it yesterday morning with no problem. I have used that same .nbh file since I started rooting RC30. Did you try using the one I posted?
T-Mobile HTC One successor to my T-Mobile Sensation 4g Successor to my TBD HD2 Successor to my EnergyRom TP2
OS: [FEB 15] ViperOne 5.7.0 | 4.19.401.8 | Android 4.4.2 Sense 5.5 |
Kernel: ElementalX 13.4 Beta
and don't forget to thank me if I have assisted you in any way