Graham you are more than welcome to come to the seminar, it is true that the demonstrators are paid and you shouldn't have any problems sitting at the front with binoculars, just like an oversized pair of spectacles
every disability is different, I use crutches you use binoculars, it's how we overcome the disability that matters (I'm as capable as anyone on my knees or in a chair) and I take my hat off to anyone who doesn't let a disability get in the way, we simply have to do things differently.
The last Axminster event in Nuneaton I went to there was actually 2 totally blind turners "listening " to the demonstrators sat down as close as they could , I must admit I was very impressed by this and got talking to them, his wife took me to their car to show me his turning ability and I was gob smacked how well it was turned (like an exhibit), it was 18" tall by 8" wide hollow form vase and even though he's blind he could easily turn by feel incredibly accurate , inspirational.
Hope to meet you at the seminar.
Kindest regards