Hi 

I want to cover my plug with matte finish to make a matte surface mould, but I found only acrylic or polyurethane or both mix together matte paints or clear coats. How do they react to Easy Lease? Does somebody have experience with acrylic and polyurethanes with Easy Lease?

Matte finishes are usually bought as an additive that you mix into any 2k clear coat. 5% for a satin gloss, 30% for a full matte, or anywhere in between.

As for compatibility, there is no blanket rule. Most 2k coatings SHOULD be fine, regardless of whether they are acrylic or polyurethane or acrylic urethane,  or whatever. But some are not. Some are not until they are fully cured, which can take weeks or a good bake at a high temperature. You really need to do a test with the specific coating you are wanting to use. Look for one that specifies high chemical resistance and quick cure and you should be fine, but i would still recommend testing prior to committing to applying gelcoat to a beautiful pattern!