Or this?
We just made some hoops from 1/2 inch SS tubing, attached to the upright on the pulpit, into which the propane cylinder base fit, and then secured the tanks with bungies at the top. Completely "vented", obviously, as were the regulator and fittings. The hoses led through sealed fitting at the deck edge and then to the appliances, one for the heater, another for the
stove, no extra inside connections.
Not sure about the ABYC legality....