I think this page is relevant https://audax.uk/static-data/participation-in-non-aukacprm/
It's relevant although this wording:-
"
DIY organisers will only accept such events if they conform with similar standards to AUK events, so they must be non-competitive, have recognised controls that ensure the registered distance is completed, and support is not provided on the route.
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is not as specific as the old site:
http://www.aukweb.net/diy/diyfaaq/#19"
FAQ19: I have entered a cycling event that is not an AUK, BRM or LRM event. Can I also ride it as an AUK DIY event at the same time?
Possibly, but read on.
Other cycle events may be concurrently ridden as DIY events providing the normal AUK requirements for DIY events are met. Riders should submit a DIY Perm application to the DIY Organiser and subsequently submit ‘Proofs of Passage’ for validation as normal. Include details about the ‘other’ event in the additional information area of the DIY application form. Where the organising body ‘validates’ the riders participation in the event, such validation might, with the prior agreement of the AUK DIY organiser, be used as ‘Proof of Passage’ for the AUK brevet. Factors which need to be considered in assessing whether the external event is eligible for inclusion in an AUK brevet include:
Distance - the ride must conform to AUK regulations regarding controls, distance and the collection of appropriate ‘Proof of Passage’.
Support - this would follow the usual practice for audax events in each country. In the UK, personal support is not permitted outside of designated controls and riders travel to support, not support to the rider.
Competition - the event must be non-competitive, as required by AUK regulations and insurance.
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So, being able to draft other riders on VR300 or DD is no different from entering any big Audax like PBP or LEL and working in groups to finish the ride. Everyone riding an event like that has equal access to this as there are plenty of people who they can form groups with (although those who are faster will have more options).
[Have created a new thread:
https://yacf.co.uk/forum/index.php?topic=112596.0 for drafting e-bike discussion rather than derail this one.]