I will admit that my first couple brews following that method resulted in slightly lower preboil grav then expected, which is common of full volume mash BIAB brewing. I also will admit that following this method I had to keep my OG sub 1.070 in order to fit everything. One thing I started doing was reducing my mash volume by 1qt and heating that quart to around 170f and using it to "rinse" the grain bag after it drained out to mimic a sparge. I didn't have to do this all the time nor did I find it increased my efficiency any however it did allow me to push my OG potential while also giving the grains more room in the kettle resulting in better color extraction. After experimenting a few times I found I only need to do my "pseudo-sparge" method with very dark beers and/or beers of higher gravity. It usually wasn't a problem for me because I have a preference for lower gravity beers anyway. As far as specialties and their total percentage in the grain bill, yes I did have to reduce them slightly however it also really opened my eyes to how little specialty grain you actually need for color and flavor contribution. Even my imperial oatmeal stout recipe uses less then 15% of the total bill for specialties and it's got plenty of color, body, and flavor. When thinking like a homebrewer you will throw absurd amounts of specialties into your recipe to guarantee color and flavor because it only costs a few more cents to add an extra ounce or two. Well since I brewed professionally before I ever homebrewed I find myself thinking like a cost-minded business person which means you want the most result for the least dollar. That mentality, combined with the great opportunity of having free roam of commercial equipment, has shown me time and time again that you can drastically cut your specialty grains down and achieve the same result. A good example is the oatmeal stout I mentioned above:The early versions of that beer consisted of around 30% specialty grains which lead to poor attenuation. Through trial an error I was able to reduce the specialties to less then 15% without having any noticeable impact on color, flavor, or body. This in turn lead to much higher attenuation which then allowed me to reduce the base malt used as well. When everything was all said and done I was able to produce a beer that looked, tasted, smelled, and stored (shelf life) exactly the same as the "test" batches but at a dramatic decrease in raw ingredients which is the difference between making money or not on the pro side and fitting everything in your kettle on the homebrew side.
I watched a food network show awhile back about the worst cooks in america becoming the best cooks in america. The one host kept shouting the entire time, "think like a cook people! Time management, pacing, maximum ingredient efficiency and usage! Think like a cook!" With that being said... think like a pro brewer, even if you are not one.
Edit* My long winded response didn't answer your first quesiton lol, sorry. I don't have my small recipe book with me to check but off hand I would say I averaged around 1.75-2lbs total per batch, less of course a specialty heavy beer like an oatmeal stout. This process has caused me to ditch sparging entirely on the commercial side in favor of full volume no sparge mashing and I consistently hit 80-85% brewhouse efficiency and consistently exceed 90% attenuation.
