It’s too generic a question, but Edinburgh-London via Birmingham tickets with a Coventry split have been allowed in the past when the service has been diverted via the Trent Valley and not through Coventry, for example.When using split tickets, are the tickets still valid during disruptions if the train is diverted and doesn't call at the "split" station.
Including when a service is delayed enough for stops to be ripped out, including the station where you split at?
(For example a Waterloo - Exeter train running nonstop from Honiton to Exeter Central with a split at one of the intermediate stations)