I tried the RF Gesso many years ago and "thought" I had followed the instructions. However, I had adhesion problems after using it - ie, the encaustic painting detached from the gesso and I had to scrap my paintings. I'm sure the product can be used successfully - II would just encourage you to read the instructions carefully, and since I used very thin layers, perhaps it is best to apply thicker layers. Ampersand Encausticbord panels come already prepared with RF Gesso and they are amazing! So, obviously the Encaustic gesso works - I just failed to follow the instructions, most likely.
Please keep in mind that Encaustic gesso is NOT the same as Acrylic gesso. You should NEVER use an acrylic gesso if you are painting in encaustic, and you should never try to combine any form of acrylic painting with encaustic painting.