Do you have a source for the suggestion that the third fast service from Manchester to Sheffield might start from "Liverpool, Blackpool, Chester or somewhere else" rather than from Piccadilly?
I attended 3 rounds of public consultation about the Hope Valley Capacity Scheme and also the public inquiry and have masses of paper produced in support of all of them. I note that documentary evidence is absent regarding where the extra service would start and finish.
The question was asked more than once and the answer was always evasive. Network Rail is tasked by the DfT to provide extra paths and capacity. When they exist it's someone else's job to decide whether to run any extra services, on what routes and by who.
However, suggestions were made of likely start and finish points. Simple Piccadilly to Sheffield wasn't the assumption and the question has been asked of TOCs since.
It's easy enough to suggest places but capacity on tracks to go west of Manchester is only part of the issue. Platform capacity for terminating trains is another. We know turn round times are critical to operate reliable services.
In my previous post I mentioned Chester, Blackpool and Liverpool as possible destinations. More recently Liverpool is the place I've heard suggested most often, always verbally.
On the east side destinations such as Leeds, Hull, Lincoln and Leicester were suggested. 3 of these could fit with existing Northern services.
But first we need to get started on this modest scheme which was being planned at least 15 years ago. The time it's taken doesn't auger well for completion of Platforms 15 and 16.
Resolve one bottleneck and it's inevitable we'll move the problem down the line.