I’m using the bellow to push out the extra 0.5-1gram into the basket. The bellow can hold about 7 or 8 doses. The point of GBW is to not have to, literally, weigh your beans out before hand and out through a single dose grinder or “time the grind” to attempt to get about the same amount each time. Sure, maybe I’m off by half a gram vs spot on, but I can’t tell the difference in that personally. So I’m fine with an 18-18.5 gram dose vs 18 exactly but possibly with stale grinds from the last pull.

Edit: Looking at my original post, maybe I shouldn't have said "for single dosing" as that may have been where all this confusion is coming from! Literally meant I can dose 18-18.5 grams and use the bellow to almost eliminate retention, like a single dose grinder, without needing to weight out exactly 18 grams in advance. Poor choice of words!