Oh yes.. there is nothing wrong with tridents, they are among my favorites... THIS Trident is quite young.. that is ALSO not a problem..
Broken down into to loose, crappy “formula”... Every METER of green, foliar, or “new growth”.. will thicken roughly 1cm between the spot of “protrusion” and the root mass..
So basically, every new METER you grow of leaves/chutes, thickens the trunk 1cm BEHIND it...
It’s about “T” in this equation... how much time it will require for a tree that size to push out enough leaves to thicken the trunk to your desired range... It will take some time.. but you will get to be VERY involved in it’s development.
Basically ..T’will be fun.. but a longer term project..
If you want pretty, aged trunks (That you see on benches.. or collected from the wild...)you gotta figure, those have ALREADY been growing 20-500 years before we even SEE them...
If you put it in a grow box, make sure the BOTTOM isn’t getting too cold, fertilize the HELL out of it, shape not chop and pay close attention to root health.. you’d have a nice trunk (3-4”) in 5 years, easy.