Try lowering the idle speed 50 to 100 RPM and see if it gets better. The trans should pull only slightly at idle. Your tach may be off. Also try idle mixture 1/8 TO 1/4 turn either way and see what happens.
All lowering the rpm is going to do is make it shake worse in gear at a stop, ask me how I know.
As for the tach being off my idle is set directly off of the plug wire with a digital tach, which at most can be 20 rpm off.
Idle mixture either way changes idle but no change in pull from being in gear.
Not sure if it will make a difference but it's worse in reverse.