Dunno if it's possible but I'd love to be able to Ponder and construct a contraption in my head, see how it works, and then write it down as a schematic. It would be amazing to be able to tinker with things without having to spend resources on them.

Sounds really cool, could also be implemented as a sort of editor if they make this an api for other mods to use.
Only problem might (Im not an expert so idk) be resource usage, you would be rendering and ticking an entirely separate world almost.

Yea, that seems cool.

In Factorio for example you can place Ghost Blocks that are just a see through versions of original blocks, but they don't simulate, render, obstruct walking, etc - they just render as gray blocks and help you position and fit the build together. You can save the ghost blocks to schematic though and copy/paste parts of builds as any other really built one - they just don't use resources and disappear when clicked (don't require any tools). I think that building in Ponder would be too easy and would take most of the fun from ACTUALLY building the contraption.

why not just like, go into a creative world?