Hi Ms Wolffie,
That link kind of confirmed what I was thinking. It seems to me, the 30mm mount pictured turns your machine into a dedicated nose cone type engraving machine.
If your familiar with nose cone engraving, the adjustable nose cone rides against the work (under pressure) and the bit cuts at a depth controlled by the amount of preset adjustment. It seems a pain to change back and forth? (engraving to routing)
Hope that makes sense, English my only language and with a combination of bad grammar and punctuation, surprised anyone can understand
P.S. I'm not personally interested in the mount myself as it won't fit my equipment but the spring loaded engraving tool has possibilities although probably wouldn't use enough to justify the cost?
Good luck, what ever you decide.....