The Bus Back Better report explicitly mentions PlusBus (page 61):
Which aligns with some of the thinking here.
Through ticketing should also be easier. A degree of through ticketing between bus and rail is already available under the PlusBus scheme, although its overage and availability are limited. We will promote PlusBus better, and work towards extending the range of destinations available under it and making
PlusBus tickets available as e-tickets and mobile tickets, so users can start their journey with a bus trip without needing to have paper tickets posted out or collected in advance from a railway station.
Which aligns with some of the thinking here.