another thing might be downshifting the automatic one gear below the cruising overdrive gear when you have the A/C on and want more performance-if that doesn’t overrev the engine beyond red line. give the poor tiny engine a chance to pull both and automatic and an A/C. Or put a Turbo on it to make it act like a larger engine when you step on it. Lots of people are doing that these days.
Most excellent solution; many of the cars I have driven with Auto trans, small engine and A/C had that included from the factory. I noticed it on Pennsylvania hills in a rented Ford Tempo cause it got very hot and humid inside the Tempo on long uphill’s on the north west Pennsylvania hills in the summer- cause the A/C was cut out then it came back on the downhill side. 