Hi, thanks for your reply.
In fact, the FEFLOW run takes exactly 4 min to finish (steady state, water flow only).
This FePEST run I was asking for, ended after 130 hours of simulation. (sadly the results weren't satisfactory, due to constraints). The model calls aren't related to the time of simulation in FEFLOW, due to the 4 min don't match with the calculation you just made. It's a different thing.
And, indeed... by adding pilot points the time required skyrockets.
Kind regards.