Thank you very much for posting this.
I will get started on new dungeon tonight. I am going to try from the outset to make it VTT friendly.
Edit: the tutorial has already paid off. On pg.3 "press and click the "Alt" key to force straight lines to be drawn"
This solves one of my frustrations with using Xara. I had been using the pen tool to draw straight lines. The fact that Xara is ready to make 2-d and 3-d objects out of anything you draw with pen, only annoyed me.