Not sure if anyone will find this handy or not but it's pretty cool.
There are 2 Golden Ratio/Section Tools here. The one that seems to be working the best is the 1st one, "Mid-Point Origin". The Origin point is at the tip of the yellow triangle. As long as you are using the Transform Layer (M) tool, you can can transform it by any handle and it seems to maintain the 1:1.816 ratio.
The second one, "Edge Origin" has the origin point at the yellow point... at the edge.
In Moho, I sometimes check my scenes against the Rule Of Thirds overlay, and have wondered why other useful compositional guides and tools haven't been added.