When barriers are configured to accept advances, do they validate the day only and not the time? So would they, for example, let someone through several hours before their train or several hours after it has gone?
I was wondering that too. I suspect it depends on the type of ticket since AIUI tickets with 2D codes can include much more information than CCST with mag-stripes can. If so, it should be possible to programme the gates to accept barcoded advances at appropriate times (only) and reduce the number of rejections.
I also wish the industry would start to issue machine readable railcards (either ITSO or 2D coded), which could be read by gatelines when checks are wanted. SWR, and no doubt others, regularly set barriers to reject all railcard discounted tickets, which is another passenger-unfriendly annoyance. You block the people behind you, you have to back out and go and find a gateline attendant, who then often barely glances at the ticket (or asks to see the railcard) anyway. And yet again the passenger is made to feel they've done something wrong, especially if they meet the other sort of gateline attendant, who thinks anyone whose ticket is rejected by the barrier must be a fare-dodging criminal.
It would take a little while for people to get used to having their railcard ready at the barrier as well as their ticket, but if the message said "scan railcard" rather than "seek assistance", it could work more quickly and not make the passenger feel in the wrong.