> Keeping a command history from the start of time and re-executing all of it to undo one step?

Someone needs to play around with NLE video editors. Because yes, that's what they basically do.

The video editing steps are all items on the "timeline". When you hit the "render" button, the computer goes into overdrive: spinning up a bunch of threads (maybe even GPU-kernels) and actually calculates everything.

What you see in the preview-screen doesn't always match the final render. The preview-screen is just a quickie-calculation, much like how 3d programs (ex: Blender) have a realtime renderer (see Eevee) vs the offline, more accurate renderer (see Cycles).

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From an NLE perspective: the GUI is basically a glorified editor of commands.