I'd love to try this in a tail, but man, I have a feeling between the scales possibly creating more surface area and drag, and the weight of the silicone out of the water, combined with the fact that most tails are made with softer blade monofins, well, I know I'd flop like a fool with all that....

I think a fabric tail with a really stiff monofin would have the best chance at this. Well, those things on a mer with a great core.... (so, definitely not me, lol)