I’m a little wary of plug-in solar in the US. Some of the bills propose allowing 1200 watt panels which can overload wiring depending on what else is on the circuit and how in the wall wiring is run. Limiting plug-in panel wattage to, say, 400 watts might be necessary
Microwave on a dedicated circuit above counter in kitchens and gfci protected per code
You’re not putting a space heater on your kitchen counter
And once again youre supplying up to 1200w, not drawing 1200w. Any power supply system will just be matching the load being drawn
I really dont think this is the degree of a problem you think it is
I think the issue is that, if you have a circuit designed and protected for X, then put Y solar in, you can get a situation where X+Y is flowing down some of the wires. It’s more than they are rated for, but the breaker doesn’t see it.