I think I am right is saying that a helper riede can be up to 2 weeks away form the event itself??
For a ride this long (homologated by LRM) yes. Shorter rides it's only a week either side, can't remember where the cut off between the two is (1000km?).
There was much clamour for, and interest in, a helper's ride in the run up to LEL 2013. In the end it was just Pat and Don who rode it. Many people did various DIY perms to check various bits of the route in advance but only those two rode the whole thing in as a single ride to get homologation for the ride proper.
Route checking on its own is a grey area; clear enough if you have spent two or three weeks toiling up and down the country checking over sections of the ride. Less clear if you ride the helpers ride and say you are 'checking the route' eh whilst doing so.
I don't see why it should be a problem for a ride like LEL. Helpers rides are far harder mentally (people are more likely to DNF given the lack of support and encouragement), physically (for those that ride as a group and share the work out) and logistically (having to manage proof-of-passage and plan places to eat/stay) all of which can take more time than simply falling asleep on a school canteen table seconds after eating the food that you didn't even have to pay for.
But, more importantly, allowing people onto the helpers ride will get more people doing long distance cycling since the space they would have taken up on the ride itself can go to someone else. This works for LEL because it is guaranteed to sell out with the riders limited to the numbers they are.
For rides unlike LEL allowing more and more people onto the helpers ride may reduce rider numbers on the actual day, so I can see why some organisers wouldn't want that, but they still need to keep a few people happy who are helping on the day or being the one or two people performing the route check. But if a group of 10 riders want to ride the week before because they genuinely can't turn up on the day (even to help) then I'd rather have them out doing a big group route check than not riding at all (although I'd expect them to pay some, but not all, of the entry fee).