Jack , you certainly have the right Spirit’/attitude for this ....
I’m using beaded foam on the FoamStream ... I’ll be using 3.5” thick sheets , because I want the superior insulation factor , a little more Bulk , and I'll have a little extra thickness to sand and round as needed .. this is the 2 lb/cu.ft. density bead board , not the lighter “shipping" kind so is pretty sturdy (same density as the Blu and Pink ) ... but it is Messy

.... and the foam dust and beads stick to EVERYTHING , skin , clothes ,hair ... static electricity ... just the nature of the beast ...

(Blu and Pink really aren't any better , the dust is just finer) Surprisingly , the beaded board foam sends very well , not gouging out beads as we thought ,.... easy to get a smooth surface ... all thoroughly tested on those paddleboards ...