Anyone ever considered whether you can take the e-bike concept of adding peddle-powered/e-bike motors and controls and creating a peddle-power trike? The trike motors and props apply power as long as you apply peddle force; you stop peddling to coast. You use the same motors as e-bikes and batteries… four motors with four batteries. Mount it all on a fixed frame (motor/props on a swing-up armature on the trike that can be lowered flat for storage). Fix on the batteries and plug in, attach the parasail, and start peddling!
Steal this idea and design it!