Sorry Adam,
I have played around with helicopter set-ups for over 20 years, as a silt rig, as a first choice for short or long distance, with or without the dreaded l-core, with slack or tight lines and it is responsible for a lot of funny takes and indications.
I definitely set it up right for long distance fishing, I don't mean a normal chuck, I mean fished at around 130metres, the line as tight as I could get it to the indicator, and I still ended up with aborted indication and a lost fish when the fish simply kited left. I don't use back leads at all.
This was two weeks ago, but I can give other instances from 20years worth of use.
Other anglers have also commented and said the same in articles in the press, and I don't think we can all be wrong. I remember one in particular as the angler concerned was fishing Wraysbury and was out in a boat checking his rigs down