At takeoff thrust it takes up to a slow count of ten to get the rudder trim right. I think pilots should simply remember the trim should be steered towards the direction of the live foot as they fly the SRS. They can subsequently slowly release their foot pressure to confirm the beta target has been centred before putting on the AP. If the beta target is not yet centred, further adjustment of the trim will be required. Personally I would not look at the trim index while I am trimming out.