(1) Hard shifts are almost always due to lack of sufficient vacuum to the transmission modulator. Since the problem goes away once the car has been driven awhilem it's probably not the modulator. You need to monitor the vacuum to the modulator (tee the line and use your Mityvac or some other vacuum gauge). Should be 12-15 inches Hg at idle and 0 at full throttle.

(2) Your sentence "The ALDA was bypassed and the sensor is set to let the turbo engage at lower RPMs" does not make sense to me at all. Perhaps I'm just tired, it's late. You can "adjust" or "remove" an ALDA but "bypass?" What is that? Additionally, there is no sensor that would "let the turbo engage at lower RPMs." I'm totally lost trying to understand what you are trying to say here. Sorry to be slow on the uptake tonight.

(3) I agree that your IP is probably not the cause.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970