I understand the points you make Irving. If the target audience is the beginner then surely it is worth taking the views of the beginner - and I am totally a beginner who has made nothing CNC, just read a lot. From my perspective wood is good and metal is difficult (can't think of a suitable rhyme). For others it will be different and they will prefer metal to wood.

The common skate carriage is easily made because in the basic form you saw a bit off, drill four holes and bolt the bits together. As you go more complex then more chance of error or frustration.

And I do have a drill press.