Every IQ micro and battery you add adds more ability to deal with current surge requirements. On my 8.5Kw system with 30KwHr of Enphase LFP batteries, I can handle turning on AC when I have full sun and partially charged batteries without going to the grid.

AC is a difficult load. Get the inrush current here: https://www4.enphase.com/en-us/support/faq/how-support-hvac-... and you will be able to figure it out.

Your refrigerator will be fine. Its locked-rotor amperage requirements are small compared to AC.