How come Liverpool Street are out of the scope given it is a major station? (it is considered a Greater Anglia stationed, but is owned by Network Rail) It might have to do with the fact that TFL doesn't want to use scanners in their system so this is why journeys via through London do not allow tickets which have to be scanned. But it still gets me when they give me the option to sell barcode tickets to a gated station without these scanners (i.e. Stratford) as you have to be see staff to be let out.
This above info may also apply to Merseyrail.
There is also a thread from
December 2016 which could have used the orange background at the top and bottom and shows the BR logo at post 21-22. I thought bartickets started around early (~January to April) 2019