Factory data reset actually does not remove root from the phone, you would have to fastboot for that. So if you are just doing an FDR and you have all your other stuff backed up then you should be fine.
Doing a factory data reset would remove the VooDoo app anyway so I think it would delete the root backup you made, then you would be worse off.
Worst case scenario you lose root and you just root again with the Razr Utility version 1.8 or 1.81.