Can I get ECMLink to control a Boost Control Selenoid? (BCS)

Using ECM Link: Yes. There is a write up on how to hook up the BCS to the ECU allowing ECM Link to control the boost values.  You can set boost by gear, rpm, etc.

Guide on everything related to ECU Boost Control using ECMLink: https://www.ecmtuning.com/wiki/boostcontrol

Here is now to install the BCS: https://www.ecmtuning.com/wiki/bcsinstall