Today's weather forecast was for blustery to become gale force and so I walked to the pool rather than driving to Hatfield. Ultimately the forecast was worse than reality and the really strong winds hadn't arrived some hours later.
Anyway the pool offers the opportunity for drills and practice in a more comfortable situation than in the middle of a lake. So, with my left arm being on the brink of problems it seemed a good time to focus on rotation to lift my left side more. Naturally this leads into breathing on that side too. After the usual 200m-with-legs warm-up I did 3 sets with favoured right side breathing, bilateral breathing and finally alternate lengths with left and right breathing. Naturally I was using the pull buoy to ease the load on my arms and retain good posture. Significantly I went at the same pace for both right-sided and bilateral breathing although I needed a single strike more per length. For the final set I was tiring (so out of practice) and so the slow pace for left-sided breathing is not conclusive.
In terms of technique I was aware of a falling right leading arm with left breaths, especially when working that side. My perception was also that I had an untidy body twist in that direction rather than a nice neat roll from the hips.
Over the time I was aware of my shoulder abut it didn't become troublesome, or indeed painful, so this intensity and volume doesn't seem to be a problem.