I had an AHA! moment and it worked pretty well. Welded my wax model
sizing seam clear thru a thick cross section to the center with no
messy oozing from a hot knife. Careful light touch (no pun intended)
at wide aperture and moderately low power/time even blended/polished
it nicely, no burs or sandpaper needed. Seemed to work best with an
angled approach rather than a straight on perpendicular shot.
Imbedded soot was a small problem which I think could be eliminated
with some practice. This was yellow wax, might be different for
green/purple/blue.
I really just expected it to blast a hole clean thru. Go figure.