Ongoing vibration issue
That's a lot of money for motor / trans mounts.
I had a 92 Chevy lumina, it had rubber isolated struts the hold the engine inplace.
One was bad so I decided to replace it with a piece of bar stock.
You would have thought I put a 500 ciu V8 in the thing, the entire car shook!
Since you are throwing parts at it I would change out the mounts to stock and see how it feels.
Still could be the trans rotating assy!