My curiosity has been tripped by some of the units/systems now selling for less than $500, although those may just be suitable for wood burning or logo'ing leather items.
Who has purchased one and used it for polymer work? I have had about 5 grips done with this method over the years but by folks who had the higher end units that did both metal and plastic engraving, big enclosures, cost thousands, etc.
It has become such a PIA to ship the lowers that are the firearm to those plastic surgeon guys as opposed to the days you could ship it direct yourself, I would be tempted to get into grip stippling for my own use if these things are now truly more affordable, workable and not that hard to set up and operate. I have zero interest in using a wood burner or breathing those fumes, that method doesn't fit my hand/eye skills either, tried it many times. Talon grips would miss the abundant sales of their Pro material in my case.