....The main skill you need is to consciously let go of tension in your body until it is habitual to be relaxed while you play this pattern (or any pattern for that matter). If you try to solve the problem by rotating your arm more without addressing the tension, you'll just end up rotating a tense hand and you'll still struggle, if that makes sense. Rotating, in itself, is no guaranteed solution.
I'm working on all three of these , there is some special attention needed to pull off what you describe in that first mov of the 2nd sonata (my focus in summer is the third one while I polish up the e flat and f minor having taken a break after juries on these )I'll give it some thought and try to get together a piano next week. And maybe record a few things I do Good piece ,glad to see someone on here working this one
Thank you for responding. Is simply being conscious of tension enough to dissipate it over time? I became acquainted with this piece from the Gilels recording on DG. He played this part with incredible speed (though still in the Allegro range) and evenness. I do notice that the top voice comes out more in his rendition. Maybe the trick to alleviate tightness it to play it more lightly overall and place more emphasis on the top notes. I notice that I still feel some tightness in the muscles between my thumb and forefinger & between my forefinger and middle finger the next day. Though maybe it's exhaustion rather than tightness because I hadn't been playing for a while before attempting to work on this piece. Anyhow..