Remember that sometimes it takes a while (a few days) for the thermal paste to set.
I applied a thin coat to begin with (when improperly seated), and noticed temperature decreases within a couple hours (from 76C to 68C idle). I fully expect that the idle temp will decrease from 43C. I did go from a thin coat of AS5 to about 3x as much though.
Will it set faster if I leave Furmark on to pump a bunch of heat to the GPU?