I will have to run this one again, as even on the recce ride 3 weeks ago, I was pushed for time, so wasn't able to hang around at the Memorial. If we'd got there earlier on the day, there was a Spitfire patrolling overhead, as part of the Battle of Britain commemorations.
I have got a slightly more direct route from 2 years ago, although that goes up Hollingbourne Hill (just past Maidstone) which is about 15% at its steepest. I think User10571 & Adrian said a few rude words after that one.
However, having just had another look, you'll be pleased to know I've found a way to avoid that, so that it works out at 85 miles overall, and misses out Shooters Hill as well. If we just have the one food stop, just past Maidstone, then that would give more time at the end.
Perhaps a weekend nearest 15th September,
Battle of Britain day?