New member  - SERUG Salisbury to Exeter Rail Users Group,  so yes please two track, if you have some spare money!!
We have been working with Network Rail on their Continuous Modular Strategic Planning (pre GRIP^▸ (Guide to Railway Investment Projects)) group to research and identify where the track doubling should be actually situated.  Maybe Dinton to Tisbury, and Whimple for starters, the latter allowing Devon Metro to operate (GWR^▸ (Great Western Railway) service Barnstable to Honiton max).

It took over 20 years for the Axminster doubling and platform to be delivered, so we work with a healthy amount of cynicism, but much energy to find a way of double tracking where affordable and necessary, and funding of course by HMG and the Treasury.
  Our web site www.serug.co.uk has it all!