I don't usually use soy wax, but with the cost of cocoa butter I am revisiting it. That is to say - my experience with soy wax has been very limited. I don't think the lard is the problem, as it is one of the slowest fats to trace. I use from 30 - 45% lard, usually 35-40%. Soy wax has always made my batter move much more quickly, although I just tried it at 5% and my batter stayed fluid. I also like to soap on the cool side.
You could reduce your soy wax by 5% and add that to the lard. Then, either eliminate the shea or reduce your liquid oils by 10% however you like.