This was not unknown, Taunton used to work like this, at the west end local services from Minehead, Barnstaple and Exeter arrived on the Up side, either in the bay or in the Up Relief platform. They then shunted back across the layout, and propelled into the Down side bays for departure. In loco hauled days a pilot loco specifically handled this drawing back, whereupon the train loco was released to the shed, but it continued into dmu days.
This shunting back across the main line absorbed quite a lot of main line capacity. On summer Saturdays in particular, to avoid this, trains were diagrammed so these locals from the west drew forward and just backed into the Up bay, to carry on to Bristol or Yeovil, and the equivalent in the Down direction.