Hmm..I'm trying to find the capacity numbers but that's probably going to be difficult.
I would normally say trust this resource so OC Register for DLR pegs the capacity at 276 people. I'm wondering if someone has taken a photo of the max at WDW because OC Register in CA says there's a sign posted on the outside (I wasn't looking for that when I was there so I'll trust that there is actually one). I haven't been able to locate the information for WDW's version though. I remember it being rumored at 150 way earlier on in the years but that would seem quite strange to be over a 100 people difference between the parks so yeah not completely sure.
What may make it a "looks can be deceiving" thing is that there is a lot of standing room between the bar and the standing tables and at other restaurants you just don't have that as everyone is sitting down.
According to Disney BOG can hold 550 people at a time. Even in QS mode I don't think Disney downgrades their estimates for how long people might stay at least not in half. I don't disagree that people probably use less time when not at Dinner at BOG but Disney may not factor that in when it comes to ADRs allotted in a given day but that's purely my opinion.
I think in my mind I was considering that the turnaround rate for Oga's throughout the whole day is probably much faster due to the time limit than BOG is on average so even if capacity is lower they turn over the tables quicker allowing more people to come throughout the entire day than anticipating X number of people being there for much longer at other restaurants. It would be quite rare indeed that someone would be able to stay 90mins at Oga's with a posted max time limit of 45minutes but Disney would probably anticipate at least some people in a given day even in QS mode would spend around that time (maybe at least 60-90mins) at BOG.
That's not me disagreeing with your thinking though because I can see that too. Either way I'm sure y'all with have fun

--Oga's was the highlight for us when we went to DLR (well we only had 1 ride so can't comment on how Rise is).