Whats the go in wiring in a external boost control unit such as a AVCR or a Blitz Spec-R item etc ?

Has anyone gone down this path?

The ecu boost controller has been struggling (read: unstable) with my particular setup. Iv had the car tuned numerous times, neither has corrected the situation. I use Lane to tune the Tek.

Flooring it to full boost from stop - it holds and controls well.
Part throttle and gradual boosting it is very very unstable.

theres a 3-port solenoid in use already.