The issue would be getting the crossings in the passing loops on the single line via Axminster to coordinate with the crossings in the passing loops on the Barnstaple line. I think you'd need an elongated stand at Exeter St David's to get it all to work.
I do think some extra services to/from a London station would help improve traffic on the line further, though traffic is improving year-on-year anyway. It's a shame that the Barnstaple end of the line has been severed as it was also possible to reach Ilfracombe, Bideford and direct to Taunton via. South Molton previously, by rail.
The issue with how the current line is set up for an hourly service, most trains have a very short turn around time at Barnstaple (usually around 5 mins or less) to get them back to the passing loop at Eggesford. I think the line needs infrastructure improvements but with an hourly set up, trains from London would either have not enough turn around time, or would have to sit at some sidings (if there are any functional sidings left) for over an hour. The timetable changes after 15:27 from Exeter St. David's to allow for the following trains to call at all/more stations.
If anything does ever come of the line in the future, I think they should have a semi-fast service calling at Crediton, Yeoford (x), Copplestone (x), Morchard Road (x), Eggesford and Umberleigh (x) and Barnstaple alternating with a request stop stopping service, but it should be run like the Avocet line to Exmouth, in that a semi-fast service to Barnstaple would become a stopping service on the way back towards Exeter (and vice versa), as it would even out the services overall. If there were a couple of daily services to/from London, IMO they should run fast, calling only at Crediton, Eggesford (for operational reasons), possibly Umberleigh and Barnstaple.
We could even go the whole hog and run the hourly Axminster to Barnstaple service, with a portion splitting at either Exeter or Credition (if possible) to Okehampton a couple of times a day, at peak time only. Would it be feasible or possible to re-open Barnstaple to Ilfracombe, calling at Braunton en route? Currently, 6 double decker buses an hour run to Braunton, with 3 continuing to Ilfracombe. I could see a market for a rail service.
Okay, so I might have got a bit carried away
