A/C compressor cycles?

Hi,

Sorry for the long post, but here is the short version:
What would be a normal On and Off A/C compressor cycling time at idle?

Here is the longer version with the full story:

I have a question about the A/C Cycling on my 2012 GT Premium.
I recently noticed that the the compressor is cycling on and off very often at idle and don't really recall it was doing that before.

It's actually very easy to figure out since I can hear the A/C clutch engaging along a little RPM drop.

Basically the A/C compressor seems to be engaged for like 10 to 15 seconds and then disengage for 5 seconds and so on.
I can only notice it when idling as it's basically impossible to figure it out when driving.

I asked to my Ford garage during my regular service during the checkin process and he said, yeah that's normal during this warm weather.
Well it' also doing it when it's 73F.... so I'm now a bit concerned.

I was thinking I may run low in Refrigerant Gas so I decided to take a look at the Low Pressure with one of the A/C Pro recharge kit, which would also allows me to refill if needed.
I actually misread the gauge and added to much refrigerant and it worsen the cycle, it was like every 2-3 seconds On and Off and the RPM decreased so much it almost stalled the car.
I removed some of the gas and check the Low Pressure again and was back to normal but my car still cycles 10 seconds ON and 5 seconds OFF like previously.

I mean the A/C is working wonderfully, I have cool air very quickly.
I even took the temperature in the vent with a laser gun and depending where the laser is pointing at but I can read between 0F (!?!) and 32F, so it's cool enough.

Still this cycle doesn't seems very normal to me so I'd like to get some feedback and compare with you.
Could it be a pressure sensor issue somewhere?

Thanks