Yes, forget it. How big should the machine be?
That dubious concept isn't as easy as it looks. I think they have a gantry Axe on Y (if the normal X-Y is correct) only, because Hermle have a patent for a centralised Spindle. Gantry have no advantage against 1 spindle in the middle, except in a really large machine.
And your control must handle 3 of it. Can it do this.
The same for X and Z. This construction is ok, if you have a spindle with a ton or more. If not its much too complicated.
And the Z axe don't work, you have 4 guiding carriage (I hope the word is correct, the slider on the linear guide) 4 or eventually 3 is correct, but not in these layout.
You need 2 sliders per linear guide. And if you want 4 side by side each must
parallel within a rather tight tolerance.
If its for yourself and you don't want to sell it, then you can make it with a central spindle.

A gantry spindle brings no advantage, but much more effort, each Motor and driver must bought double.

The concept with the u-shaped bed is good, but all other too complicated. Unfortunately I don't know, how I can add a pdf-file.