I'm partial to 400A's but I've had customers supply me with Korky's, BrassCraft's and OEM products designed specifically.
Those American Standard Smart Valves, take them out in your yard and burn them. They have a history of failure and AS is aware of that.
Always check your static water pressure before dealing with any water supplied device in your home.
There's a reason why your doc's office does 2 things before addressing any health matters, *blood pressure and temperature*
He/she is looking for underlining symptoms that lead to a possible core problem.