Here are the 1st to 2nd and 2nd to first shifts pressures explained. From here you should be able to work out the rest of the gears. To speed up the shift time you increase the shift pressure. You would normally only change the disengage (also known as off-going) pressure if a gearbox has been built poorly and has trouble disengaging the gears.
This guide is a draft, please do not take it as gospel.
UPSHIFT
ZF00567
Shift pressure 12
Pressure applied to 1st gear clutch to disengage 1st gear on upshift.
ZF00603
Shift pressure tables 12
Pressure applied to 2nd gear clutch to engage 2nd gear on upshift.
ZF00623
Shift pressure tables 12
Pressure applied to 2nd gear clutch to engage 2nd gear on upshift in performance mode.
ZF01446
Shift Pressure offset 12
This is an offset to the pressure based on temperature. Eg if you want to firm up shifts at certain temperatures you would increase this pressure.
DOWNSHIFT
ZF00605
Shift pressure tables 21
Pressure applied to 1st gear clutch to engage 1st gear on downshift.
ZF00569
Shift pressure off-going clutch 21
Pressure applied to 2nd gear clutch to disengage 2nd gear on downshift.
ZF00633
Shift Pressure 21
Pressure applied to 2nd gear clutch to disengage 2nd gear on downshift in performance mode.
Here is a tree diagram (we are looking to add this to the editor to simplify things) which may help explain which tables do what.
Line Pressure
ZF00739
Line Pressure 1st gear
This is the pressure applied once in gear to keep it in gear. If the gearbox is flaring or slipping (you can log the transmission slip %) then you would increase this pressure.
Note that you can very quickly destroy a gearbox by changing these pressures to too high or too low. Be careful.
Where you see "reduced downshift" or "reduced upshift" this is apparently performance mode shifting (I do not have a ZF to confirm this). Looking at the increased shift pressures in these maps this makes sense.
To increase the ZF rev limit changed the two following scalars:
ZF02463: Engine Speed threshold for NMOT monitoring.
ZF04094: Upper turbine speed threshold.