After much "jiggery-pokery" I've managed to get a code based pre-compiled node graph working for my AI's pathfinding. Much better than my previously scripted solution. It's hugely faster to implement, mostly automated (so less errors/typos/general-cockups available on my part) and the paths are pre-compiled so the AI don't have to work out their routes on the fly.
It took a bit of integrating into my AI system, but we got their in the end. Thanks go to Gabriel Notman of Bolton Uni for making the original resource on design doc available.
This test video uses the stock TGE CTF map and assets (hence the slightly bizarre fantasy buildings), with my first gen AI model and animations. Blue lines are the Node Graph, green lines are the set path.