You can solve this by creating a separate gui for the text nodes and assign it a new material and set adjust mode to Disabled (select the root node of the gui and change both of these in the properties panel). With a new material and adjust mode set to none it will be possible to render the text nodes in the same screen space as the game objects using a custom render script. I have created an example that shows how to do this:
Try it here:
http://britzl.github.io/publicexamples/text_on_go/index.html