@Expressflight & tws123 - thanks both for replies, useful. When we look at rail link services from London out to either EGKK/LL/SS and of course a handy DLR jolly from Tower quick switch at Canning and in no time you're at EGLC, you quickly see a potential business argument to rapid rail link EGMC into London.
The current service is terrible both in terms of the very dated rolling stock plus the lack of early and late services. I suspect there are capacity constraints in trying to run a fast train service on that line into L'pool Street especially at peak evening rush hour where pax are eager to jump on flights between 16:30 and 19:30.
You have to question the current 10 year plan for SEN and recalibrate to yield higher yield margins. It's a Stobart under utilised asset which certainly appears to lack effective and efficient management. No doubt Stobarts commercial lenders are observing with particular interest. It will be hard for the company to get away a bond for any expansion if there is no tangible evidence of growth being delivered in a consistent manner with sustainable margin generating routes for all involved.