Having been a mechanic on [only] two LEL's, I'd be very happy to stick by a judgement based on those two enjoyable experiences :
So there we were waiting for the riders to come in at St Ives [first control], and I remember saying to Clive and his son Max, "see these early fast riders coming in now - they won't be coming anywhere near us. Know why? Because for them, it's an unnecessary waste of time, and they are not the sort of riders that mess about wasting time".
Course there are always exceptions and the unexpected unfurls - like the German chap whose dura-ace hub bust and vorspung's seat-post snapping - it's the nature of a mechanical vehicle with so many moving parts that are subject to wear. These things can happen. But generally speaking, faster, experienced riders do not piss about hanging around with bike mechanics. I know who the experienced AUKers are. And I don't see much of them. I see them come into the control, I see them eat and I see them leave.
Get further down the pecking order and it's a different story.....of ALL nationalities!!
Nice thing about LEL is that is requires no qualification. And that's an attractive platform for cyclists that want to have a crack at it, chance their arm and leap into the unknown. But that potential lack of experience can bring it's own problems for riders, and they're the ones that suffer because of it.
Personally I wouldn't necessarily change anything, but I would really emphasize on the web-site for 2021 all the points that have been made in this thread about spares etc. And stressing 'Look, it's up to you.... but if you come mechanically unprepared, you might have to wait ages to get anything fixed, the mechanic might be really busy if you suddenly need them, and you're going to be wasting your own valuable time - and time you most definitely have not got'.