Technically, the LHBS is crushing correctly and we are overcrushing, but that, like most things, is subject to opinion. Ain't no way a LHBS is using a .020" crush like me though... (I dont crush for efficiency, I crush for faster rate of conversion)
To me the bar is 70%. If you're near that, cool, as most recipes are based on that. More than that is gravy and bragging rights. 60% or less and you need to fix something. Back in the day when LHBS milled my grain (twice) and if I did everything perfect on a perfect day I could hit 70%, but it was rare. There were plenty of times I missed it bad. Was it bad crush, bad malt? I dont know, I did everything right... I no longer have these issues milling it myself. Regardless of the number, the key is consistency
I do think a 3G batch in a 10G cooler is pushing it but if you are holding temps good then you should be OK.