195 degree OEM 1995 Magnum 5.9 V8 thermostat failed after 5 years in 50/50 Ethylene Glycol mix coolant when the brass arm cracked which cocked the valve partially open.

180 degree “Balanced Flow” Robertshaw thermostat failed in the closed position about a year after I began using Evans NPG coolant.

205 degree Stant “Standard Grade” thermostat failed in the closed position after 9 years in NPG coolant.

I would think thermostat design would have advanced to where they last 20+ years when coolant is changed on schedule.

Evans NPG coolant is supposed to be “Totally Non-corrosive” to iron, aluminum or brass compared to water, EG or PG coolants.
But I have wondered whether it could chemically react with the wax in the thermostat.