I'm with your wife on this one. There are industry standards on shallow/deep transitions and sidewall to bottom transitions for any area designed for "jumping" or "diving".
Once you move out of these standards any accidents fall on your shoulders, hence why the PB wants a signed waiver.
The other party to get involved in the discussion is your homeowners insurance company. I can bet the idea of you signing a "waiver" will be a non-starter from the insurance company based on liability issues. You need to understand that you may have different policy premiums or even need to find a new insurance company once a pool comes into the picture as some do not want to cover the added liability. When we purchased the house with a pool our company (USAA) sent an inspector to the house who verified fences and child proof locks on gates leading to the pool.
No need to worry. I like the idea but it is NOT being considered in my build
I came across the build for TX-C and saw he had done it and I loved the idea
Page 5 post #85 has a good shot of it after gunite
Page 6 post #107 has the pool filled with water showing it off
I also have USAA and inquired about any issues and premium changes in my planning for slide/grotto etc. Was told I have no limits/restrictions and they just recommend I increase my policy coverage when completed