whoops sorry you're right, I want to chalk that mistake up to it being a long day but yes, 2", my mistake.
As for the oversized QD hole, I did find online that there are those sling cups you mentioned that you could install, so perhaps its more accurate for me to say I would prefer that they used the (what I think is more common) QD size that I've plugged into several of my other stocks/railsystems so you don't need to buy said cups.
For this outting I was using the iron sights, my RDS had some issues so I had to remove it, I would expect that as I get more familiar with this firearm and with an optic I should be able to tighten up the groups (mostly 5rd groups, sometimes more).