Just to be clear, I wasn't advocating one way or another. And I wasn't saying the efficiency change would be large, but I said it would add up. On a 15P beer, on a 15 BBL system, 3% is somewhere in the realm of 15-20 pounds of grain. Every 3-4 batches you would be using up 1 more bag of grain than you needed to. If you have a tasting room, the beer prices can easily absorb that, even if you're just a distributing brewery, you can likely absorb that.
Yes, it is completely dependent on equipment. It will depend on how much deadspace there is in the lautering vessel, etc. I was simply expressing the opinion that walking up to any random brewery's brewhouse and deciding to batch sparge has a high chance of having a lower efficiency than is normal with that system because the overwhelming vast majority were designed for continuous sparge, obviously there are exceptions, like the folks who have Meura setups.
I was echoing the sort of sentiment Horst was expressing in his anecdote about attempting to brew an American style ale on a German system and experiencing a 20% efficiency drop.
Ultimately, if you're buying a new brewhouse, you want a system designed around whatever technique(s) you have adopted in your brewery. If you're stuck with an existing system, your technique choices will be somewhat bound by what the system was originally designed to handle. Continuous vs batch sparging is only one of those decisions, pellet vs whole, already milled grain vs milling on site, cleaning under pressure or not, caustic or alkaline+acid, etc.
Even if you happened to walk into a German brewery where you were all setup for batch sparging and then decided not to decoct because 4 out of 5 Dennys agree that it doesn't make a difference, you would experience some serious problems because the system was designed around decocting (again just as Mr. Dornbusch shared).