So, Decided to sacrifice some my precious loft stored walnut. Planed a piece of walnut down to 0.43" and threw it into the Glowforge. I did not expect it to work and was pleasantly surprised. Not as easy to cut as the Oak in my previous topic.
Still the Glowforge was able to cut it in one pass. There was significant charing on the edges and the cut/kerf is a bit ugly. But with a quick swipe of fine steel wool to dust off the char, it came out looking just fine.
Edit: Just learned that there is the possibility that this pre-release unit may have a higher power tube intended only for the Glowforge Pro. There is no way for me to know.