I used mods like litematic, item scroller, minihud and carpet (stackable shulkers) it runs really well on the deck... I built all the blocks separately in creative and did the build in survival, it has taken hundreds of hours and still going
Looks lovely! Didn't think the deck could handle mods but looking at the specs, makes sense.
I wonder if my modpack I've been playing works on deck so I could at least get a few more things done while watching kids (the pack being Enigmatica 6 Expert, works on 1.16). It's a chunky pack though, so I'm doubtful.
Quick edit: was reminded of my pack because of the big tree. E6E ends with a giant tree growing in your base you have to nurture with obscene amounts of stuff you automate.