Are all three bins seed or some fertilizer? If you had fertilizer and wanted to control the bins with fertilizer a strip module would be needed and a liquid module for UAN.  Flexicoil air carts usually have electric over hydraulic valves and they need to be changed to a pwm or hydraulic servo valve to be compatible with the strip till module. 

On the seed side you would have one serial connection available with an application rate module connected to the Flexicoil controller to run vra prescriptions.

A Direct Command Raven adapter harness kit for a 440/450 could be purchased or you could by pass the Raven 440/450 wiring harness and purchase a Direct Command Complete kit so it is all Ag Leader components.  Price is pretty much the same between the two harness options. 

You would then be able to use autoswath (if you have fertilizer bins no autoswath avaiable on serial control) and have the option to run vra prescriptions.  It would be best to call tech support and talk with them on your setup to ensure you could make it work.