Engraving with a diamond drag engraver is not a core function of CNC routers, which were what we were selling when Carbide Create was first released.
Note that we’ve done a number of features which probably folks would be willing to pay for such as Image Tracing:
which are in the free version, so I don’t see that the Free version will be crippled, and as noted, there is a work-around (doing both contour and texture toolpaths), and the reason Engraving is a Pro feature is that it is not a basic routing functionality, which is what is being offered up for free.
Please write in to sales@carbide3d.com if you have any concerns about pricing or feature availability.