Snap guardian to straight lines
After drawing your guardian, square or rectangle, Confirm it, then ask us if we want to "Snap guardian to straight lines". Make it clean and straight, not all jaggy from being hand drawn.
Then it would be nice to see the new straight lines and be able to push/pull them for final tweaking. Final Confirm, start playing.
S. Christian Collins commented
I've attached a short video showing how this could work when setting up the guardian. Holding down a button (A?) would show a ghost line to the current cursor location from the previously drawn point. Pulling the trigger would then draw that line, similar to how most graphics editing software works.
This would make setting up the guardian both faster and more accurate, but also result in a lower-polygon guardian grid, perhaps reducing its hit on performance. As the guardian appears to cause stuttering in the v25 and v26 updates--particularly when the couch is also mapped--any possible aid to performance would be welcome.