Strange, my son also uses Beersmith 3 and the recipes he has sent me always separate the mash water salt additions from the sparge water additions. Every time I build a recipe (or just select an AGK NB recipe), it seems to designate all the salt additions to the mash water and none to sparge (other than maybe a small amount of lactic acid).
I am thinking I must have some setting off but cant seem to locate it. The batch of kolsch I did I ended up treating the mash water as directed (which was the same measured amounts of salts that were calculated in the water tool for the entire 8+ gallons of water (RO base). So I am confused but will dive into the help section to see if that will enlighten me. Thought I would ask in case someone has worked through this already.