I did the same one 
That was a pure power course really (that aqueduc KOM needed a bit of attention not to split the group but it was very short, and the second half was pan flat and super straightforwards).
Re your Q - that’s not what 10% difficulty means, “difficulty” is a bit of a misnomer - more correctly it’s “gradient realism” or something (although gradient simulation realism is a bit debatable anyway). At 100%, when there’s a gradient in Zwift that’s 10%, Zwift tells your trainer to simulate 10% gradient. At 50% trainer difficulty, when there’s a gradient in Zwift that’s 10%, Zwift tells your trainer to simulate 5%, and so on. The reason 50% is the default is that some cheaper/older trainers can’t simulate grades above 8% (and there’s up to 16% gradients in Z).
So all it affects is the gradient simulation on your trainer - the flywheel still weighs the same.