Just as a minor point - the postal service at the moment is quite useful for getting a brevet card to an individual for permanent events - as I'd probably baulk at driving to Wales at some ungodly hour of the day to provide a rider with a brevet card at their chosen start points
Historically (I'm guessing) the brevet card was useful as evidence that a rider is part of an organised event and therefore would be covered by AUK insurance, although its possible that the law has moved on and an email exchange and GPX track would now also be sufficient evidence - it would be great if someone had some guidance on that.
Once I've got rides GPX tracked then I would be happy to offer GPX entry and validation and, as long as the rules permit go completely paperless, to cover those who have no current fixed abode. (As an aside, this would deprive me of one useful piece of information on permanents - the receipts show where people have found food, ATMs, etc, which is good info that I can pass onto other riders of perms that use the same control towns).
Alternatively, you can ride a Super Randonnee, there your proof of passage is photographs of your machine at various specific locations on the route to prove you were there, which is really challenging when you have to find the appropriate part of Denbigh Castle in the early hours!!
Again to respond upthread, I would consider using others' track logs, but I'm not convinced of the savings. I can't upload them blindly, because they may well have gone off route accidentally, deliberately (because they knew of a great cafe a few miles off route or had, on the longer events, organised camping/B&B off-route), or taken a longer alternative that looked brilliant to them but would be utterly bonkers to someone else. But I have committed to do it and by the end of this year, the Cambrian series will be tracked on RWGPS, prioritising any new entries that I receive. There's one exception to that, which is the 6C Super Randonee which is already tracken on Openrunner, because it has to.
All tracks will be issued with a risk warning, which will be an addition to the standard sheet that I send to all first time Cambrian Series riders to make sure they are aware of the risks they are undertaking. Again there may be some who think this is unwarranted, but they should talk to RUSA about that...
I'm not sure how much this helps the OP, but I've heard a reasonable and impassioned argument as to having GPX tracks for events and will respond accordingly.