Just a heads up:
BEFORE my engine fell out, my car would grind 2-3 shifts just like yours, predictably and constantly. The only thing that would stop it was a deliberate effort to slow down the 2 to 3 shift. This sucked, and made me dislike the car quite a bit.
AFTER the engine fell out, and I got my car back, this anomaly was completely gone! Somewhere during the car's rebuild (which was only 2 days long), the dealership straightened everything out. There must be some adjustments to make, or something along those lines. Whatever it was, I'm grateful that it is fixed. Why this such a nice change of shifting prowess that I was ALMOST happy that my engine fell out so it could be fixed! ALMOST.
Moral of the story - Consider that the dealership might have a way to adjust things around. Maybe snag a technical service manual and see if there are adjustment procedures...