I'm renovating my bathroom and have durock in the tub area and green board outside of the tub area. I have the seem between these two boards planed so my boarder tile will cover the seem and be 50/50 on the durock and drywall. I've installed my drywall sheets horizontally because I have tall ceilings. I'm getting ready to tape my drywall seems and fill the screw dimples. I keep reading that it's not good to thinset over joint compound. Since part of my border row of tiles is extending over the green board which has 2 seems which will be covered with tile, what is the best way and what compound should I use to tackle this issue. I was thinking of taping the drywall as normal and just priming the drywall before tiling. Hoping the primer over the taped seems and screws will keep the compound from turning back to mud. If this would work, what primer is recommended?