My VF24 was creeping from 15 to 18.8PSI.
I ported the wastegate , same deal, more towards the flapper pivit, also severly rounded the passage into the wastegate.
No more boost creep!
Although I did have to raise the boost numbers in my utec (which were VERY low anyway) to get the same boost.
I love it and HIGHLY recommend that ANYONE installing a VF turbo, port the wastegate BEFORE you install the turbo. You will be glad you did.