Can i add an item i dont have to optimization

Hi, Is it possible whether i can add an item i don’t have yet to BestInBag optimization so i can know if that item is an upgrade for me o r not?
This would be usefull for buying items from AH or choosing quest rewards.

The upgrade finder can show you pretty well if any particular item will be an upgrade for you or not.

How i can i see a quest reward on upgrade finder?

I guess we don’t have every single item in the upgrade finder. Which quest reward? Is there any reason not to do the quest and then just see if the item gets picked by BiB?