I think you're right. It sounds like he hasn't been looking around online very much. If there are more changes you want to make, print out pictures of them. When I first began thinking about a pool in January, I think I printed over a 100 photos of things I thought I might be interested in. Pinterest was a huge help. Since I'm not great at design, it helped me start weeding out things. My tastes began to evolve. Now I'm down to just a handful of pictures left.
You may not need to do that for yourself, but it might help the PB or the designer. Today, when they told me it wasn't possible to have the joints match on the spa coping, I just pulled out several pictures I had where they were matching. The men couldn't say it was impossible then. They also seem to respond better to a picture in hand. Some cell phone screens are hard to see the bright sunlight. When they were constructing my spiral steps and bump out bench, they kept the pictures (in plastic sleeves) outside with them and kept referring to them. They had never build those two things before now.
Well, just some options to think about. And gee, you didn't even have to ask me to butt in!! Lucky you! Have a great weekend. Suz.