This is behaviour trees. What you’re describing is behaviour trees. Edit: I see later you say it isn’t a behaviour tree but this is how a lot of BTs are implemented. They don’t always loop from the root. A lot of the time according to state the root is redefined off of a branch and that sub tree is looped until going further down the tree or even into a different tree. Much like the stack you are describing.

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(See the end)

There's definitely a strong shared flavor between this and behavior trees. Almost like a goal stack in this system is a continuation or call-stack of a behavior-tree traversal-in-progress.