The problem with subtracting off the fiber and sugar alcohols is that it's not clear that all fiber is completely not digested (there is some evidence that some forms of soluable fiber are at least somewhat digested) and sugar alcohols are definitely digested, just not as well as sugar.
There is at least one sugar alcohol, erythritol, that has so little calories it's pretty neglible (.2 calories per gram). But a lot have 1.2 to 3 calories per gram. IOW, the ones with 3 calories per gram have only 1 calorie per gram less than sugar!
So I just count all carbs and don't worry about playing "net carbs" games.
Oh and Dreamfield? Total scam. Notice on the packaging that it says it has 41 g of carbs, 5 from fiber, 7 g of protein and 1 g of fat. But it says it also has 190 calories. If only 5 g of the carbs are truly absorbed, then it should have 57 calories, not 190. This is a clue. LOL
The thing is, if you test your blood sugar before and after eating it, you can see that Dreamfield has a lower Glycemic Index than regular pasta but all those carbs are competely and fully absorbed.
The Dreamfield Pasta Fraud
This is also true of that Julian 1 carb bread, btw.