Capacity limitations on the west coastway would suggest it could only be done as an extension of an existing service, but I reckon only with today’s SWR timetable .I’ve always hoped of a Bournemouth to Brighton Service. Would this be possible ?
I believe that you can arrive/depart from platform three in any direction (as long as your train is short enough) as whilst there is a full platform face (enough for 12-car I think) there is a junction in the middle which allows trains to go towards Hove but restricts the length to around 4-car.