I tested creating 100 Gold nuggets. my stats were 77% Prof and 44% Focus. out of 100 tries I had 46% success rate. in that 46% success rate, 22% were +1 gold nuggets. None of the material used was +1. I think the mechanics are off a bit. This happens on a lot of MW items and the results are always the same. The Focus seems to be the deciding factor if the Item is created or not, then the Focus is used again to see if the product is of +1 quality.
I tried again but this time with 50 gold nuggets (ran out of AD) and the following stats 77% Prof and 65% Focus. My results were 14 Gold Nuggets and 18 +1 Nuggets. Again you can see that both rates are seemingly based on the Focus and not the Prof.
If you would like to see a video or a log of this happening, I will send it as soon as I build up more AD to test again. Please let me know. Thank you.