re: Casting platform height

I did notice that, if this doesn’t work out I’ll try square tubing on it as well

Not sure there is an ideal size. Ice chest is too low and 6 feet is too high. Mine is 48 inches tall and I've fished off of a few taller than mine and I liked them.

I didn't go through many of the post in this thread, so I may be repeating others, but if at all possible make the platform collapsible or fold down. That way you have secure it to the deck and leave it there when trailering or making long runs, or in rough water. Makes life easier.