Beersmith and wort concentration during boil

I am having issues understanding parts of Beersmith.
I use a 3 keg all-grain system. I have my equipment set up in Beersmith with 70% brewhouse efficiency, a boil volume of 12.5 gallons, and a 10 gallon batch volume. I added the same exact equipment profile again, but upped the boil volume to 16 gallons.

I set up a recipe for each equipment profile above. To keep it simple each recipe only uses 35 lbs of Briess 2-row each. Beersmith predicts the OG will be the same for both batches, even though one batch collects more wort from the sparge and concentrates it into the same final volume. Beersmith shows the Measured Mash Eff. go from 48.2% to 61.7%. How does the OG not go up? I must be missing something here.

35 pounds of 2-row has a certain theoretical yield that is the most sugar you can possibly get out of it. For whatever reason, Beersmith is estimating that you will get the same percentage of that theoretical max yield, regardless of the sparge volume. So when you boil down to the same volume, you get same OG regardless of sparge volume.

I think I got it. For the 16 gallon pre-boil volume I need to make a guess (or use historic data) on what the total efficiency should be. I then need to adjust the eff. in my equipment profile for that sparge volume.

Thanks