I upgraded to Fences 3.x from 2.x because I hoped it would fix my issues as was mentioned in the features: "Use fences on modern, high DPI monitors.".

But perhaps my case is not covered here. So sad. 

My case:

Microsoft Surface Book, display 3000x2000, scaling 200% (recommended). Fences works fine on this display alone.

Adding external monitor over mini-HDMI-to-DisplayPort, 1920x1080, scaling 100%.

The configure fences window changes size when I move it back and forth between the two displays. This tells me that at least part of the dpi related programming was done in fences. 

Now the problem:

If I dedicate the external monitor as my main monitor, the fences obviously move to that monitor. However, unlike the configure fences window, the fences themselfes do not adapt to the new monitor. Instead I have now HUGE overlapping fences with HUGE text labels.

The icons within the fences do what they are supposed to do.. they change size to accommocate the dpi change. 

I believe this is a bug. One that renders fences in my setup completely useless.