The downshift blip table is not limited like IDP said, I blip mine to about 35-40%. The limitation is only for the translation table, not any of the functions using the DBW (Anti Lag, Blip, etc).
It could be that you are not allowing it to blip for long enough, I blip for 175msecs. Also, how fast are you logging the channels, if the log rate is slow it may look wrong.
How fast you can go with the cut on upshifts depends on many things, the devil is in the detail. You need to log everything to do with the shift nice and fast to get the best idea. RPM, Ignition Cut, Barrel Position, Up Shift Cut Request all at at least 100Hz.
Might need to send me an email with some logging to
mark.mccoy@motec.com.au. What gearbox is it?