Yes, do not connect the white wire for 12V output. Polarity of battery matters of course, as well as dynamo output polarity. I have tried to make the DVR2 unit as robust against faults as I can, within what is an acceptable price. Bulletproof against all connection faults or whatever is possibly feasible but impractical. Fitting the recommended fuse helps too.
One other point to watch is dynamo belt slipping. I had problems with this initially with Hawker kit. I find the belt has to be really quite tight with the higher load put on the drive by 12V operation.
Tone, I will be more than happy to test your regulator free of charge (bad pun there), or call me to discuss