Share 'Selmi One & Injection Plate?'

Looking at the Selmi one and the Plus and on up, there appear to be no differences in connection where the injection plate would mount for filling molds.  In fact, we have a reducer attached to help with flow issues.  There are even 2 sets of receptacles on the back to plug in the warmer.  So, why will an injection plate not work for this model?  Anyone tried it?  Had one made?