I learned the rotational draw from Arne's video, and if you haven't watched it, or haven't watched it lately, it would be worth your while to watch it again. I thought I was using the rotational draw for several years, but I really wasn't, until I watched his video again and paid attention to the fine points.
One of the fine points I missed the first time around was that the rotational draw is accomplished by initially raising the arms slightly higher than the anchor position, and then drawing back and downwards to a point slightly below your anchor. The string hand is then raised up to the anchor. This upward movement is no more than 1/2 to 1”, and is done after you are at full draw with fully engaged back muscles. Any effort to reach full draw with a pull in an upward direction makes it difficult to engage the back muscles. (Arne might go so far as to say impossible, because, as he puts it, there are no back muscles up there to engage).
Anyway, I’m dwelling on this particular fine point because it might be a reason for your shoulder pain, if you are doing it incorrectly.