I got this to work oddly enough by doing these things
Create a mesh instance, and select "Use Alpha" in the Material options (or if you're doing a shader use DIFFUSE_ALPHA, instead of just DIFFUSE)
Create a mesh instance as a child of the above mesh instance, and set it to "On Top" (I recommend using the "create outline mesh" tool to do this, also setting "unshaded" to me makes it look nice)

If you'd like object an object to be in front of this effect, set it's material to "use alpha" also
This is the way I found out how to hack around it, but I wouldn't expect this to work everywhere, or to be supported after 3.0 but who knows