I have found the very useful Balancing Radiators post by Dotty from 2016 (Balancing Radiators Thread. - https://www.plumbersforums.net/threads/balancing-radiators-thread.87115/), but it doesn't say what to do with the TRVs while adjusting the lockshields in steps 7 and 8. Do you just leave them wide open until all rads are balanced or adjust them to your desired temperature for each rad as you go ?