The original LaserWriter was actually a more powerful computer than the Macs that used it, at the time of its release.
Debugging on a laser printer definitely was a challenged, and used lots of paper.
You're right that NeWS made it a lot easier to debug PostScript code interactively without killing trees. It had a command line debugger, but was great for making visual interfaces too! Here's a visual PostScript programming and debugging environment I made with NeWS:
The Shape of PSIBER Space: PostScript Interactive Bug Eradication Routines — October 1989
Abstract
The PSIBER Space Deck is an interactive visual user interface to a graphical programming environment, the NeWS window system. It lets you display, manipulate, and navigate the data structures, programs, and processes living in the virtual memory space of NeWS. It is useful as a debugging tool, and as a hands on way to learn about programming in PostScript and NeWS.
https://donhopkins.medium.com/the-shape-of-psiber-space-octo...
I think it's what we were trying to accomplish. My work with Forth was on Apple II computers while my contact with PostScript was to make printers do things they weren't supposed to do - such as printing fractals - because, for some time, they were the most powerful computers we had at the office.
Apart from that, the syntax seemed awkward for things more complicated than rendering text in predefined positions, but, then, I didn't have any development tools similar to what was available with NeWS (when NeWS was still hot).