I think I'm right in saying that the formation has always been single track, and so the creation of extensive stretches of double track will a) have to precede wiring, and b) will take several years. If the enhancement teams are to be kept active, then a more shovel-ready project is required. I understand that there is a group examining what BR-era 'simplifications' could be reversed to make operations in the Glasgow area more robust.
BTW, all the recent posts should be moved to a different thread under Infrastructure.