Thanks to everyone for some very insightful comments!
It seems like maybe I should just let the engine run its course, due to low odds of success for cost-effective repair efforts.
I think I'll start by sending the next oil change out for analysis. If it only indicates bearing wear, then maybe I'll open her up and swap in new bearings. If it shows elevated iron though I guess I'll accept it as a hint to either shop for a new commuter car, or to double down and learn how to swap an engine.
My number one limitation for home car repairs is actually that I have a tiny single stall driveway at the top of a long hill. If I jack too many wheels off the ground she starts rolling sideways, and I quickly learned to tie a rope to my creeper too, because it only takes a few seconds before it's rolling away faster than I can run.
So in addition to not knowing how to swap an engine in the first place, I'm also picturing losing control of the engine hoist, chasing after it in vain as it hurtles down the driveway, and watching it careen into a parked Mercedes at the bottom of the hill...