Question can I get some help plz

[Omnikron702]

I have a 2007 NBS Silverado with a 5.3L & a k&n cold air intake. I purchased the intune basically to disable the AFM, but I decided to use the 87 octane tune, with the firm shift tune as well. I'm pretty new to using tuners, and I haven't messed around with any independant settings.

My question is how do I adjust the shift pressures or shift points? (not sure which needs to be adjusted)

When I'm driving around at slow speeds (like 20-40 km/h) the tranny seems to shift hard (or clunky) almost through 1-2 and 2-3 gears. I know that I selected firm shift, and I like it when driving around at normal speeds, but if I'm not on the gas it just seems like it "clunks" through low gears.

Does anyone else have this issue? or does anyone know how to change or modify it? Is it safe too keep on firm shift?
Are there any other setting I can adjust It a my daily driver