BIAB question

I am new to BIAB and beersmith and am driving myself crazy trying to figure out how to setup the profile I am looking for. I only have a 9 gal pot so its hard to 5 gal batches with more than 10 lbs of grain at the 3qts/1lb. What I want to do is setup a profile where my ratio is 2qts/1lb and then add remaining water to preboil volume. What are most of you using for mash profile? I estimate that my useable volume is closer to 7 gal vs 9 gal. Any help would be great.

I am just getting into all-grain BIAB recipes, but I modified the set up for 5-gal mini-BIAB and saved it under a separate profile.  I am only doing 2-1/2 gal recipes, so it fits quite nicely into a 5-gal pot with plenty of room to spare.  I set up the efficiency and water adds as I had done under my partial mash recipes that I brewed and will modify the settings to take into account the actual measurements I get while doing the all-grain recipes as I go.  This worked extremely well during my partial mash recipes.