Thermostat failure Mr. Gasket High Flow

I put a high flow water pump on the 340 in my Mirada. If you put a high flow component in one part of the system, I think you ought think about the rest of the system. After some research, I went with the Mr. Gasket Co. High Flow thermostat. 132 miles later, the car begins to overheat; fortunately on a few miles from home.

A couple of thoughts on this:
*I don't think plastic belongs in a component such as this.

*We originally were going to drive the Mirada to a cruise-in, Friday, about 150 miles away. But, a few minor things caused us to cancel the trip. Even though disappointed in not going, that decision kept us from a roadside breakdown due to the thermostat.View attachment 1714946762
Is there an update on this? What type of impeller does Your "high flow" water pump have,...is it composite? Did you cut apart the thermostat and see the remnants of the part
that failed? Did you find all of the pieces, or..........?