Couple of other cost effective tricks for checking high thermal load in temperate climates..
You can lower the cut-in of the termistor range of the collant temp sensor by bridging it with a parellel resistor..this gets you a 100C cut-in of high fans [ instead of 105/107 spec.] when the a/c condensers passive heat starts to effect coolant temps [ which it always does with the cond in front of radiator]..this is a $2 modification that we have been using for years.
The other is many use a cabin sw that shorts the high pressure sw manually..this is nice if you want to get a jump on temp creep-ups at will.
Good as a high temp saftey measure , regardless of using the a/c or not..great if towing, etc..
This also allows for normal operation when not being used b/c it does not change any of the circuits stock design. { Had to throw that in there before I get jumped on that one..]
Also, you can jumper the R15 dropping resistor to get high fan instead of low for a/c operation ..this does require running a heavier wire back to the low fan relay as the original will not carry the higher amp load of high fan [ you will notice high fan and low fan have different size wires , as low fan does not have the high amp draw of high fan, due to more resistance in that circuit from R15.}
And lastly, don't make your coolant ratio on the high % range...water transfers the heat away lots faster than anti-freeze does ..40/60-h2o is fine in temperate climates..
These are just simple , short $$$ mods and are not for the adverage owner .. but more geared to those of us who are tech inclined and know these circuits.[disclaimer]
High side temp/pressure checking and air flow has a lot to do with getting high output out of an a/c unit, regardless of what the refrigerant is.. and the main reason manifold condensers are so popular in beefy a/c systems.........