Fairly sure the lines are supposed to be paired by fast/slow rather than direction. Adding platforms at a point where you'd want a fast cross country or London train to be able to pass the Gloucester local would seem to defeat the purposeI was at Stapleton Road on Friday, first time for some years. I wondered whether platforms 3 and 4 would be reinstated to serve trains to/from Gloucester. The wall supporting platform 3 appears to have been reconstructed during the track work so reinstating the platform should involve relatively little work.