Hi jepokey. Sorry, can't help you with the first 2 questions but with the TI support, could you mount something like I have done with my cart here....

I have also used this boggie board rubber for my roof racks. Using some 'Unistrut' as my roof racks the profiled rubber slots into the unistrut groove as you can just see in this photo.

I have 4 of these which just slot in under the hull and works perfectly.
Hope this helps. At least it will get the thread back up to the top of the list for you
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