Ah, good point. I think in all the text above I failed to explicitly mention that you’d need to use the WidgetInteractionComponent to actually use the coordinates to get interaction.
If I remember correctly, Riley’s approach just displays the GUI as a texture. So there’s nothing to interact with. So you have to point a WidgetInteractionComponent at the widget you’re taking the texture from. It’s kind of janky, which is why it’s a shame that 5.5 no longer supports drawing widgets directly to the spectator screen without drawing to the HMD. But it does work.