If I were King Of Decks:
They would all be made of polymer boards, struts and support beams(?)--I'd command all grandfathered structures slathered in TruOil after sanding then texturized appropriately. The next step would involve "rattle can" paint. I've found Thompson's Water Seal is mostly expensive bullshit.
If your deck receives a lot of sun/weather it will become a crisp source of tinder. You should be ever ready to replace 2X4 slats and be vigilant of looming strut failure; exponentially the higher the deck; dependant of age and type of wood:
My experience is all with pine: Your experiences with oak, cherry and walnut may vary: Also, holy shit.
IMO a walnut/free floated bbl is best served by TruOil and a few slashes of automotive paint.
Decks and gunstocks may have differences:
That is all.