The second part of my question at least can be answered please? If the desired boost is determined by default in the program using parameters that ecu should have or by ecu itself using the parameters that the new map determine?

i own an alfa romeo 159 1.9 JTDM. i try to solve a weird problem of my car using MES. after driving around 100 kms distance or climbing a mountain after 10kms, it starts to have a boost pressure loss for a sec and gain it again over and over again while my revs are steady ( just a bit of throttle us...