Those are pretty normal temps, and not all that excessive. The oil needs to be a minimum of 150f to 180f to lube and properly , and there is a thermostat in the filter housing set to 180f before the oil flows to the cooler. The Jagg adapter does not eliminate the thermostat.
You can't do much about the temps you see on the highway on a hot day short of doing some stage 1 or 2 work to the scooter. You can reduce the amount heat that builds up in traffic. Wards Parts Works fans work well on the heads, and he sells oil cooler thermostats set to the lower end of the range. And you can put fans on the oil cooler.
Down side is that all of the heat you blow off the scooter doesn't go far. Creeping along in traffic on a hot day is still going to be less than pleasant.