The standard turbo can't flow enough air to maintain the boost flat and does tail off, that is perfectly normal.. 1.3bar and tailing off is standard ppp
Mapped more like 1.45bar tailing to 1.2bar.. should make around 350~360bhp and 400lb torque once mapped.
The only minor concern (too strong a word but couldn't find another) is the ecu I would say has pulled some timing just before 6000rpm to 6400rpm hence the slight dip in the power curve.
The AFR fuelling graph looks normal for ppp and sometimes find with the ppp sports cat it is running slightly different fuelling to that picked up on the dyno.
Simon