dont bother with an SAFC either, all just bandaids.
A proper tunable ECU, allowing you to alter fuel, ignition, rev limits, idle etc is what is required.
Since you dont want to go full aftermarket, a Nistune seems like the best option.
You can do the tuning yourself or find someone who is competent in your area to do it for you.
Its likely you will gain power/torque everywhere by being able to properly tune such an awesome setup.