SunPort is presently rated 1200 watts at 120 volts, which means the largest load allow able is 10 amps. Most electronics are substantially below this rating. The main items that could exceed this are loads with a medium or large sized motor and appliances that create heat, like a toaster oven. If you overload the SunPort, it will shut off to protect itself so you should be careful about plugging in something that could overload it and which would cause you trouble if it suddenly shut off.
It is fine to use a plug strip with a SunPort but you need to be careful not to overload it in this case. Also, some loads are variable and they may occasionally spike up, even if they are typically lower. For this reason, you should check what the total load of the items on the plug strip are. Also, the phone app will allow you to read what the load is at any given moment.