OOooo.....all the pretty colors! No reason it won't work, but you do sacrificce a little flotation space in the hollow center of the noodles.
How does it compare, economically, to the cost of sheet foam from Menard's/HD/Lowe's? (I'll concede that I haven't priced that in a long time.)
You've got too much empty volume in the spaces previously filled with foam. Assuming the noodle is 2" round with a 1/2" hole down the center you've got 41% less foam in the same volume of space below your floor, so you will need to add a considerable amount of foam to other areas to achieve the same amount of emergency flotation support.
Furthermore, your hull is not getting any structural support from the expanded foam fully filing the voids and bearing against the outer hull skin the entire way, so you're more prone to developing cracks along the ribs and other hard support points where the frame meets the hull skin now that those areas are more free to flex.