I get it that some suggest the graph is a complicated/over-engineer while other suggest just stick to SI. Well, my rationale is that not everything has a SI con

I get it that some suggest the graph is a complicated/over-engineer while other suggest just stick to SI. Well, my rationale is that not everything has a SI conversion, and simple SI/hub/spoke would need you to maintain a unit -> SI (or base unit like USD in currency conversion). What I like about the graph solution is that you don’t have to use SI or base unit at all! If your graph has km -> m, now you add (updating your graph) for m -> feet, you could traverse from km -> feet. Later on, you can add nautical mile -> feet, using this graph you could basically get km -> nautical mile if you need to.