Xr6 over boost problem

can anyone help me with a over boost problem I’m having with a fg xr6, it’s running a bigger turbo with an internal wastegate and factory boost control I’m running it in open loop. It will sometimes over boost when you are half throttle and the ecu pulls timing on a gear change (auto). I can stop the timing getting pulled but the customer likes the sound it makes on the gear change, I know of other cars with similar set ups that still run the torque reduction on gear changes. Any one help me with this?. I’m using hp tuners.

How about a datalog? Details of the setup?