I spoke with the owner of the company today and he was able to answer the question about the ability to remove the thing. He basically said you heat it up with a heat gun and the goo softens (its not epoxy) and the thing will pop off and the goo will clean off. He said their instructions on an aluminum boat call for taking the paint down to the aluminum but he agreed that it would likely be fine adhering it to the paint if its in good shape, which is the way I would go. They also make a dual unit large enough for the SI/DI transducer to be mounted high so it will come out of the water at speed and the dual beam high speed unit mounted low to skim at speed. It seems like a really cool idea and I'm going to try it. Still would be interested to hear from anyone who might have it installed.
Thanks, Jeff