Your thoughts on a couple of Design Ideas

[JAZZCNC]

I've been building machines using that design for nearly 15yrs. My first machine was one of the first DIY machines I'd seen that used this setup, it also used raised sides so gantry sat directly on rails and height-adjustable bed. It works well.

Edit: This machine also had the option for a 4th axis to be fitted on the end, also a vertical fixture plate for clamping material to allow Dovetailing or Hinge and Mortice work on doors.Etc

Here's one I built about 5yrs ago.