I think it would be very difficult to hide a fat ultralight, especially if a 4 stroker was hung on the front. Maybe a D Motor. They’re semi light.I dont know that there better than a 2 stroke though. We are a little restricted up here in Canada, but not enough to complain. There’s other stuff to complain about. There is no ultralight category. It’s called light plane category. Any single or 2 passenger plane has a max MTOW of 1232# BULA (basic ultralight airman) allows you to fly any plane in that category. Training is 5 hours dual and 5 hours solo and the other usual minimums. Turn in a self declared Class 4 Medical to Transport Canada and get a ticket for 5 years. AULA (advanced) allows you to carry a passenger. I think it’s just another 5 hrs training. A buddy up here has a Sonex Onex flies with a BULA. One freedom up here that not available for US fliers is to fly across the border. With advance paperwork permission from FAA, an 180 day permit can be gotten for a BULA or AULA pilot to fly into USA. A minimum single 2 hr cross country is all that’s required. To fly into Canada, a private pilot certificate and medical is required. Sport Pilots are not recognized. Crazy, huh.