Edge hints

[micheus]

So, I want edges for the purposes of making sure the tris sit the right way, but I don't want these edges breaking the edge loops and other quad modelling methods. Is there any way in wings to get best of both worlds here?

I'm not sure how that has being processed, then we may have room for improvements or not.
I want to believe the export process Wings3D will try to find the best way to cut the quad.
But, even doing that, sometimes that may not be way we need.

If you need your model to be exported to another software using triangles, maybe you should triangulate it using the Tesselate->Triangulate (in Face mode) before call the exporter. Then, you can check for inconsistencies and use Turn (in Edge mode) to fix any problem with misplaced edge.
Or, you could cut only the face you want to decide where the edge must to be placed (creating the triangles as you need) and exporting with triangulation which will complete the task.