Things went shockingly well, night and day compared to the last time we tried which was only 2 weeks ago. We still had lots of NW but we were having those anyway with the swaddle so I don't think it is related. She actually looked really comfortable and rolled over and slept on her side and her arm wasn't flailing around. So, because it went so well I decided to do 1 arm out for nap this morning and she's been down for almost 1.5hrs now, so no issue there. Will keep 1 arm out for a few more days then try both (though she seems to be able to easily escape that other arm now, so some of the night she was doing both out).