How much am I shortening the lifetime of my car's AC system by starting it at highway speeds?

My car's HP is low enough that when I'm running the AC, I'll turn the AC off while I'm accelerating then turn it back on when up to speed. This gives me a little extra "boost" to keep up with traffic. I'm worried this may cause AC failure "down the road." Do they simulate this test mode during HVAC lifetime or validation testing? And if so, does anyone know how much it can shorten mean time between failures (MTBF)?