If it is the sort they used to do, Pegasso, they are pretty good and used a pair for my diving for a couple of years.
They are long and powerful fins. With that sort of fin you can go faster but requires more strength and can cause cramping. The position you are paddling in a tube makes this more exaggerated and is the reason tubing fins are about 1/3 the size of scuba fins.
You are also more likely to trip over your toes in the shallows. I saw this happen to my tubing partner with normal tube fins... he was face down in the water and couldn't right himslef. He was terrified and gasping for air ......though have to say it was the funniest thing I have ever seen

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You are also more likely to stir up silt.
Personally I would steer clear for tube use.