The articulation with the simple sketches used illustrates your point beautifully. A reader can confidently gain the desired understanding of your articles point just by scanning.
What I love most is how you separate the time with “unnecessary fidelity”. I have found this to be a moving scale with the developers I work with. Someone in Mumbai vs a pair developer team 1 seat over will require a vast difference of fidelity. This will lean heavily on your relationship with the said developer or team.
Client do appreciate the time saved on mockups as well. When building with low fidelity, combined with an approach of systems over screens the time saved is incredible.