The "print head" for Peachy is basically a laser which is deflected by mirrors controlled by electromagnets. The print volume is then basically a pyramid or cone below whatever height the print head is mounted at, so the higher it is mounted, the greater the surface area of the print vat can be.

As far as I know, larger print configurations have not actually been tried yet, but from the discussion we know that the Peachy team has focused engineering effort for the 1.0 printer on small print reservoir scenarios (as they should). There will be challenges in getting larger prints to work well. Theoretically, the 1.0 printer should be able to print to large areas if it is for example mounted on the ceiling in your garage (depending on the height of the garage ceiling). However, print times for a large vat will be prohibitive, among other things, so some of the optimizations discussed on this thread would be needed to make larger print scenarios feasible. That's why folks are playing around with pump hacks to replace the basic dripper, which is great for small print vats, but won't scale well for bigger vats. It's the first of several components that need upgrading to enable the larger scenarios. Bear in mind, too, that laser safety with a small vat configuration, and laser safety with something mounted on your ceiling are completely different animals.