I want to do a 5 gallon batch BIAB. So my question is in the equipment section do I just select 5 gallon batch ideal or is there a way to modify the 2 gallon batch BIAB?
You can modify the 2 gallon. I would just take a screenshot of the 2 gallon BIAB and then make a new "equipment" profile for your 5 gallon batches entering your pot size, boil off, loses etc. Keep everything the same as the 2 gallon if you don't know the other info.