I haven't ordered any of the Laminate Plates...yet...but I have done some laminates using another method. I shot some full-mold 3" Skinnies (3rd pic of Green Opal Minner), cut them long-ways with scissors, laid the halves back in the cavities on 1 side then shot my 2nd color...
If You're getting some "lift" when shooting the 2nd color, the only thing I can think of (in my limited knowledge) is, how much pressure are You applying to injecting the 2nd color? Could a little too much pressure be causing the 1st color halves to raise up?
Edit: Or, I always try to make sure the laid-in pieces of the 1st color are seated fully in the cavities. Maybe the 1st color pieces are slightly raised when the 2nd color is shot?