The 7 point limit is for the blindingly obvious reason that the longest 24hr brevet distance that can be AUK-recognised is 720km. You can ride further in a British 24hr TT but AUK won't recognise more than 7 points.
Sure, but that still sounds (to me) like the justification is "because regs". The whole 30kph thing came from the need to quell the idea that Audax could be construed as racing, and to make it easier for validation to occur. It just seems odd to me to apply the same rules to something which is quite at odds with that. Maybe I should just drop it, but...
Reg 9.7.2 is the one.
That applies to AUK events (specifically BP/BR/BRM rides). A 24TT isn't one of them.
Reg 10.1 also allows the speed/distances to be raised for BRM events if that's what ACP or LRM say. I guess this is for things like the Vedettes at PBP which have no upper speed limit. A 39h PBP will still be validated by ACP and recognised by Audax UK despite it being >30kph.
So the rule exists except where there's another reason to ignore it. Why not ignore that reg for 24h TTs too given they seem to be in the same spirit as the Vedettes at PBP?