Think this is right, basically you’d have to weigh well over 100kg before the Neo wouldn’t be able to provide enough resistance to accurately simulate the 16-17% maximum gradients in Zwift - and that’s assuming you’re at 100% trainer difficulty. Obviously anything lower than 100% is easier for the trainer to simulate anyway. You only need to adjust that slider if you want to, the realism isn’t dependent on your weight in this context.
I’m sure @GPLama will correct me if this is horse plop. 
Oh yes, that’s the video I watched. Not something I read.
Yes, then I got confused with this. Are you saying if 2 riders with different weight going up the same gradient. The trainer / zwift will send different breaking forces to the trainer?
That’s right. Zwift sends your actual weight to the trainer to replace the 75kg default. This is irrespective of the trainer difficulty slider.
The issue I am having is I have lost my slider bar and can’t generate any watts or speed. The trainer works fine in workout mode but not game mode or any organized rides. When I just use the Wahoo app I get more watts than I can handle. Not sure how to fix this
If there’s no TD slider, you paired your trainer wrong.
Did you pair controllable with ANT+ FE-C or Bluetooth?
Been using bluetooth. I think when my ride actually worked, I had my Garmin edge 520 also hooked up. I have not been running my edge, as it seemed redundant for mileage. I will try hooking it back up and running FE-C from Garmin Edge