Equipment profile for BIAB (Beersmith virgin)

I don't quite understand how to set up my equipment profile for BIAB.  I've watched the video and read dozens of posts but since I'm an idiot, I'll ask an idiotic question.
Why, if you're doing a true BIAB and not using a mash tun, do you have fill out the mash tun area?  It's not truly a mash tun but I guess it's because it's where you are mashing the grain. But, wouldn't it make more sense for BIAB profiles to have a different screen to input kettle info? 

I agree. Maybe the equiptment profile should have a BIAB checkbox to combine Mash/Lauter Tun and Boiler into one object.

Another note is how easily a brew pot/boil kettle loses heat compared to a water cooler or other traditional mash tun. My brew pot is aluminum! Sure, I can try to do a temperature mash, but heating the mash up is too finicky/uneven for me when the grains are in the pot, so I've since decided to just do an infusion mash by taking the grains out of the water when raising my temp, and then, once the water is ready, turing off the heat, put the grains back in, and cover with a lid. Some way to help calculate/accomodate for heat loss and for 2nd or 3rd step infusion temps when no water is added would be great!