Downwind hand paddle vs SUP paddle

Can’t help myself! I spent a bit of time imagining a dinghy style spinnaker that would retract into a deck kite chute type thing… I imagine it would only really be worth the time in +15kn anyway, in which case surely (surely) all of this wouldn’t be that hard. Also imagine because you’re going dead downwind with the big bag, you’d just paddle away any apparent wind and would render it a bit useless. A bermudan rig on the other hand, on a broad reach… why not? If it could collapse into the deck?? Sign me up.