I tend to change all 3 fluids at the same time in the summer and change the chaincase and transmission every other motor oil change, in the winter. I know it is over kill but "my ride, I decide". So I open up all the plugs and drain everything at the same time. I start on the jiffy stand and then move it upright, so I do both. I do notice some more motor oil come out when I move the bike upright. I will guess at 4-6 oz. or so.
I would think that those who have an oil cooler never get all the oil out anyway, so I wouldn't think it would be a big deal if there is a "little hold up".
To me, as long as you don't over fill or really under fill, you are good to go.
When I change just the oil, I don't tip it off the jiffy stand.
I think that is why the emphasis is on checking the oil level the way the manual says rather than telling you a specific amount of oil to add during an oil change. Most of the "amount" appear to me to be ballpark figures.