I realize this is a bit of a tangent from the intention of the OP, but…
For those that BIAB and sparge to hit volume:
Do you get better conversion by sparging the grains to hit volume as opposed to just mashing in at full volume?
I ask because I always get better efficiency with a higher water:grist ratio and it seems to me that while sparging may rinse some sugars, I can’t wrap my head around why I wouldn’t get that rinse by just mashing with more water to begin with. (Anecdotally, the bigger the beer, the worse the conversion efficiency. I think this is partly the reason for the advice to “adjust your efficiency down when brewing that Barleywine!”).
And while I’m diving in, does an ideal water:grist ratio for BIAB exist?