"I could just chop it to where I want it, but I feel like I'd be wasting a lot of tree that would have a 2 1/4" trunk right off the rip.."
Here's the thing--you have to learn to tell the difference between "wasting" part of a tree and simply "working" on the main objective.
The upper two thirds of this tree have no taper, no significant branching, and very little interest visually. It's pretty mediocre tree material in other words. The lower section, which you correctly emphasize with that big trunk chop is where the action is on this tree.
Here's where you are:
You can air layer the upper trunk, waiting two or three months for new roots (and yeah, you must sever the layer in late spring or summer since exposed air layer die off in winter.) This will require delaying work on the lower trunk for most, if not all, of this year's growing season --you can't really do anything to the main tree as you air layer the top.
While the air layer MAY eventually work into a mediocre tree (which will have to have taper forced into it after the nebari has been developed-which could take a few years in-ground).
The bottom line --is the air layer section worth sacrificing development time on the main specimen? In this case, I'd say no--but that's me.
The old "you've gotta break some eggs to make an omelet" applies here. You're not "wasting" anything by simply chopping the trunk and getting on with it. You could be wasting time by air layering this...