This is a great project, always something I wanted to have a go at but haven't found the time. Absolutely love the theory section especially.
I have previously done some testing with hobby servos (https://domwil.co.uk/posts/servo-performance/) to measure their dynamic performance (bandwidth, response time etc), is this something you have considered doing as a before/after to see how much better you have made it? It would be fascinating to see.