I've changed to 10 gallon batches and my manual systems of batch sparging needs to go (I'm getting older & grayer everyday). I'm considering doing full volume mashes in my cooler, as most of my recipes will be well below its capacity, and using a pump to move the strike water from my keg/brew pot to the cooler. I use a false bottom in my cooler so can't crush as fine as BIAB. What hit (if any) can I expect on my efficiency doing a no sparge, full volume mash? I'm usually around 75% mash efficiency.
I did something similar for the same reasons.
I have lost around 5% in mash efficiency, well actually the mash is just as efficient, the percentage of extract is what fell. But I decided it was worth it for me.