Again, what PlusBus are saying is most buses, not most bus operators, and in 6 of the 7 examples you have given* the operators accepting PlusBus appear to be operating the majority of the bus services (Dumfries is an outlier with only 1 operator
accepting PlusBus, and only operating 1 route).
To be valid on most buses, logically it also needs to be valid on most operators. And while yes Plusbus may normally have a larger operator onboard in each zone, it still can't reasonably count as 'most buses' when there are still so many in the zone that don't accept. This is also how passengers see ticket acceptance for multi modal tickets, not at a route level but at an operator level. If you promote a ticket for an area with 5 operators, and then say it's not valid on A, B, C or D then ask someone 'is this ticket valid on most operators', I can tell you what the answer will be!
"many buses and trams in each zone" would far better reflect the realities of the overall Plusbus acceptance.
"some buses and trams in each zone" would reflect the realities of scanning onboard the accepting operators.
*The numbers of operators you claim are showing on the PlusBus website are different to what I see.
I refer you to this sentence in the post you quoted.....
Just for clarity, the number of accepting operators is based on the information displayed on the Plusbus website and I have excluded operators from the figure where they are ceased or no longer operate within the zone.
So for example, Arriva Midlands is listed as accepting the Wrexham Plusbus, how can they accept the ticket that is only valid in an area which they do not operate? For the same reasons, I ignored Stagecoach Cumbria in the St Helens zone and I ignored Blackpool Transport and Stagecoach Merseyside in the Preston zone.
In Dumfries case I gave the benefit of the doubt with Stagecoach Cumbria for the 79 service as I believe the ticket is valid on there but just missing from the Plusbus site, hence stating 2 operators.
The suppliers like Ticketer and Transmach have access to the repository of public keys. The bus operators don't directly deal with this, it's done by the ETM vendors. They're supposed to refresh from it every day.
In reality, what appears to have happened for Ticketer is that each operator-area has its own configuration profile of some sort which has its own keyset, which appears to have been years stale in many cases. These profiles can be updated, and I've gotten Ticketer to update it on request for problematic areas, but it has to be done for each area one at a time.
Thank you for this information. Very helpful to understand how some of it works.
It'd certainly be interesting to learn some more of the behind the scenes workings on this to understand what data Ticketer are using to set up the zones and add operators etc. Especially given the Plusbus website can give outdated zone information sometimes and it was has been previously acknowledged by Plusbus at meetings that the Plusbus Naptan isn't reliable either (though this was said about a year or two ago and so may have been sorted. I can't for the life of me remember whether it was at a PTIC or Naptan meeting though)