Many thanks to TCAS FAN, Shamrock7Seal,The Nutts Mutts for your informative posts,I guess it's wait and see with planning permission to be given,before we speculate
on any airline developments for SOU.It seems that if it is given then there are improvements to be made on the runway even with an extension.If SOU is to continue and develop then there is only one course of action and that is significant airside investment. We wait and see!