[sherlock9c1]

What's the rear axle ratio in the car? stock 3.08, or have you changed it? The higher the number, the firmer the shift will be with an identical transmission.

Second, I've become convinced that the light-throttle 1-2 shift in the TransGo kit is a bit too firm for just about everybody but the 2.56 rear axle cars. You can always go back to a stock 1-2 accumulator setup (orange and red spring inside the accumulator cup) with no adverse effects, and this may smooth out the part-throttle 1-2 shift for you. It will have negligible effect on the WOT shift quality.

 

[sherlock9c1]

I don't think it will. 1-2 shift quality is driven by three things:
1. the hole size in the spacer plate
2. the 1-2 accumulator setup,
3. Line pressure during the shift, AFAIK.

So it's easy to change the accumulator back to stock and see if that will help your part throttle feel. It may or may not; i'm not knowledgeable enough to know.

The other option is to adjust the line pressure tables in 1st and 2nd under those conditions and pull out some pressure. But I wouldn't do that without a datalogger, and a line pressure gauge wouldn't hurt.