The new tool seems to make some assumptions/clarifications that the instructions were not explicit about:
Routeing Point Groups: Members of a RP group are discounted if they cannot be reached without going through another member of that group. Given that double backs are allowed within RP Groups for interchange purposes this isn't really an issue.
Which ticket type: The old and new PDF instructions both mention that "one of the following" ticket types must be used, but it is not clear whether you can use any type from the list that you want, or if you must try them in the order presented.
The tool implies that it finds the first ticket type common to both stations and compares with only that ticket type, declaring invalid if it fails and not trying any further ticket types. This could possibly result in a loss of permitted routes.
Routed ticket: For routed tickets, the instructions tell us to "check carefully that the route selected is via this specific route". My understanding was that you calculated the permitted routes as usual, then at the end discarded all routed that didn't obey the routeing on the ticket. It wasn't clear previously whether the fares comparison should be done with routed fares or 'Any Permitted' fares. The tool appears to try to compare with routed fares if you specify a route, and fall back to Any Permitted otherwise.
I've not done much investigation on these points as I don;t have the time sadly
Routeing Point Groups: Members of a RP group are discounted if they cannot be reached without going through another member of that group. Given that double backs are allowed within RP Groups for interchange purposes this isn't really an issue.
Which ticket type: The old and new PDF instructions both mention that "one of the following" ticket types must be used, but it is not clear whether you can use any type from the list that you want, or if you must try them in the order presented.
The tool implies that it finds the first ticket type common to both stations and compares with only that ticket type, declaring invalid if it fails and not trying any further ticket types. This could possibly result in a loss of permitted routes.
Routed ticket: For routed tickets, the instructions tell us to "check carefully that the route selected is via this specific route". My understanding was that you calculated the permitted routes as usual, then at the end discarded all routed that didn't obey the routeing on the ticket. It wasn't clear previously whether the fares comparison should be done with routed fares or 'Any Permitted' fares. The tool appears to try to compare with routed fares if you specify a route, and fall back to Any Permitted otherwise.
I've not done much investigation on these points as I don;t have the time sadly