Hay I just came back to say that the experimental simulation nodes are exactly the kind of self referencing instruction functionality i was looking for, supposedly animation nodes might do something similar. It's quite hard to manage the context evaluation in the newer versions it seems but it opens a lot of doors to my older projects that died from a lack of this. I did know at the time nodes can be iterative not not recursive, I just didn't know where that applied fully when I was new to geometry nodes.

@Markusv Thanks for the response. You're right, my focus on the interface is mostly irrelevant. You've given me a clue as to why it isn't possible with the dead description part, I'm interested in understanding the limits. You also mention using a mesh line with a bool attribute. From what I understand (correct me if I'm not) the result of a non-field value isn't stored in the node like a variable, but field attributes can be stored in geometry. They can be used later in the tree but not earlier, and field attributes can only be "mixed" with other geometry where the number of IDs are equal.