With bi-mode passenger stock increasingly common, it might make more sense to electrify the simpler avoiding line via Treeton to allow freight to run on electric before tackling Sheffield Station in the future.
Avoiding Sheffield has a long history going back to George Stephenson who took the Derby - Leeds line via Rotherham. HS2's original route was planned similarly.
Today LSL specials usually avoid Sheffield picking up at Chesterfield, Doncaster or Swinton to capture the South Yorkshire market.
Approach to Sheffield from the south was good after the tracks were quadrupled in 1904. Sadly that benefit had been lost by the 1980s when it had been reduced back to 2, land sold off and bridges removed.
In 1950 there was a large area of railway land around Sheffield station but much of that has been sold off too. Remodelling is necessary in a tighter area, built over the confluence of the River Sheaf and Porter Brook.
To the north and east the bottleneck into the Don valley is going to be a lot harder to resolve, certainly within the scope of available finance for projects outside London.
But surveying work between Dore and Sheffield has been seen, albeit it surveying of places to site survey points.
Grayling's bimodes came in for criticism at the time but are now looking very sensible - if only EMR's can be made to work.