Do you think your velcroed surfboard leash will hold if you fall out of an AI? It seems your surfboard would not have nearly the weight/momentum of an AI under sail. I'm not a surfboarder so you will have to humor me. On a surfboard is the sail ever cleated? On the AI, your sail may be cleated so that if you tumble out, the boat may continue merrily on its course for some distance w/ you in tow. I think that may be a virtue of a chest harness tether--it would surf you along behind the boat (if you have a long enough tether.)
Actually there is no chance at all the velcro will separate, actually I have had a concern that I could pull out a shoulder, or break an arm.
First, on tack, my half paddle blade (shock corded to the side of the boat) was caught by the water and twisted back 180 deg.
I have lost a paddle off the aka support, and I now use yet another surfboard leash to secure that, also with velcro. I tested it, by letting it fall out of the support, and was astounded what sort of force is generated by a vertical paddle well under the water. My AI stopped, the leash did not break, and the velcro stayed put.