I installed grill inserts in my Jeep Wrangler for a cross country off-roading trip years ago. Mainly to keep bigger rocks from being kicked up and damaging my condenser through the very large grill openings.
Well, I can very close to overheating climbing out of Death Valley with my AC on in Sept. I had to turn off the AC. Same think again climbing at altitude in California. Again I had to turn off the AC.
I removed the grill inserts when I got to Utah because I suspected they were the cause of a brand new vehicle nearly overheating. I never came close to overheating again all the way back to Georgia.