I was curious about the best methods for engraving or etching glass.

Would a standard 6040 cnc engraver with the 4th axis and a diamond tool in the spindle do a reasonable job?

Is a laser engraver a better choice?

Anyone have any experience with engraving on glass cylinders (glasses/vases etc)

I assume that a laser would struggle with anything that is not perfectly cylindrical - i.e. no tapered glasses.