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Not about speed, it's just about having something to use if my tubeless setup fails and tpu take up a tiny amount of room compared to butyl.
I used one for exactly that purpose a few weeks ago. Additional complications were that I had to boot the tyre and it was on a tandem. It did what I needed and got us home.
I think it will work again in the same size tyre, but not in a smaller one as they stay stretched.
If you want faster than butyl get latex. TPU don’t deform so worse ride quality and much more fragile