Don't suppose anyone would like to have a bash at explaining the logic behind some of the rather draconian rules for Advance tickets?
I accept that these rules exist, but fail to see why they are there in the first place, e.g. in the case of not breaking a journey, even the part which is not covered by a specific timed train. You are only taking the same amount of travel, so unless you stray into peak time periods I really cannot see why a break of journey should not be permitted.
If I am allowed to take an earlier Merseyrail train than that suggested in my journey plan, then why am I not allowed to take a later one when my journey ends with Merseyrail?
It all strikes me as being rather "because I say so".
These fares are offered at sometimes substantially reduced fares in order to encourage the development of a flow of traffic from one station to another.
A bad example but a simple one.
LM may want to encourage people to travel from Northampton to Birmingham New St rather than London for shopping, leisure, etc because there may be unused capacity on that route on particular trains. They will therefore offer a fare at a substantial reduction.
That is the purpose of the fare - to generate a flow of off peak passengers from Northampton to Birmingham New St.
Now if the fare is low enough, it may well be actually far lower than say Coventry to Birmingham New St where there is adequate provision and an adequate flow.
Now for all sorts of reasons it is important that the ticket is not available to be used from Coventry. Some of those reasons or indeed all of them might be :-
(a) LM would lose existing revenue if everyone bought the special fare ticket from Northampton and used that ;
(b) It may well encourage additional travel from Coventry, which although in theory would seem to be at odds with the principle of encouraging travel by people from Northamption, remember that each "new" Coventry passenger is paying less than the correct fare and this represents a loss. Therefore even more people would need to travel at the reduced price in order to recoup the losses, thus cancelling out the original reason for offering the cheaper ticket.
(c) LM are trying to discourage heavy traffic to London. People joining intermediately between Northampton and New St would actually increase the flows (with the resultant loss of revenue) and the Northampton passengers would simply go back to travelling to London because going to Birmingham was just as crowded.
(d) Northampton return passengers would have less chance of getting a seat because of the number of local travellers - remember they have increased because the fare is cheaper.
So how do you get round all those issues ?
Well simply you offer the ticket, but with very strict conditions, one of which would mean it is not valid for a break of journey. This has no impact upon Coventry to New St passengers because New St is their intended destination. It only becomes an issue for someone wanting to benefit from the fare but travelling to a station which is closer but in comparison more expensive.
I am reluctant to even address your MerseyRail query simply because ticketing holds no interest to me and in any case I have neither the time nor the intention, nor the wherewithall to review your ticket conditions. It may well be however that the ticket is issued on the basis of being used only on specified trains where there is a low usage. Travelling on a later (or even an earlier) train would feat the purpose of offering a specific ticket for designated trains.
As far as I know, no TOC has yet employed people who look to see if they can come up with ridiculous terms and conditions. These will be associated with some specific niche that the TOC wishes to use be it developing a traffic flow or filling underused trains. When you have the reasoning behind them then the ticket restrictions make more sense.
They only "dont make sense" because people want to try to use them outside the specific reasons for which they are offered in order to gain pecuniary advantage.
Similar reasoning and logic is used by airlines who make it cheaper to fly to South America via KLM and Schiphol rather than from the UK direct simply in order to support a reduced UK to Schiphol fare to encourage that flow of traffic.
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