In my reading I've been seeing the technique of not mashing the dark grains, like in a stout, and steeping them separately, then adding that to the boil, so as not to lower the mash pH too much. That got me thinking how I could easily incorporate this technique into my full volume BIAB brewing. Could I do the mash with the base malts like normal, then pull the bag. Then while the bag is draining, add the dark grains in a separate bag to steep for 15-20 min, pull that bag and bring to a boil? See anything wrong or potential problems?