3 train ops barely ever increase capacity at bgw. Apollo is the biggest benefit and it's not even that much. I've never not stacked in 3 train griffon.
Is this because of how slow the riders are getting on these days? When I worked at Kennywood Park back in the early 2000s on the 'Exterminator' (indoor 4 across spinning wildmouse) a good team could operate it without stacking if we took the belongings from people as soon as we saw them on the platform that way when it was their turn they boarded immediately. Why people have so much crap is beyond me. We always had one of the longest lines in the park and it was amazing how fast the line would move if we ran 7 cars (usually 6) and tried to sit 3-4 to a car at all times. This annoyed some guests but oh well. I was always amazed at how bad some people were at driving. Stacking was like rocket science to them, and if you didn't do it right you had to send some cars around again. I grew up around large model train layouts so maybe that helped me.
I always question why parks don't look towards Disney with how they board rides that have rows of people. Everyone stand on a circle with a number. This is where you will be sitting no exceptions. Another thing that I feel would help is storage bins on wheels that get loaded on the queue side keeping guests from crossing the platform, getting tied up with the exiting riders and having to make their way back to the train. Don't get me started on those with flip flops. I didn't get to ride Griffon last year so maybe these things are implemented and I just don't remember.
I will say to all the BGW ride ops, you are all significantly faster than the KD team. I've been to KD many times prior to 2019 and the only standout team was usually the intimidator. Sorry KD people.