I guess it's best if Jeremy starts the repo himself, and we contribute to it. But I agree; cannot understate the importance of solutions to make the best use of this book.
Thank you for sharing an interesting paper. The similarity between Raft and Viewstamped Replication is easy to gauge. The original Raft paper too acknowledges this similarity. OTOH, the similarity between Paxos and Raft is not very apparent (to me). The paper in the link seems to predate Raft, and only considers VR, Zab and multi-Paxos.
A similar learning experience for me was when I was exploring Apache Calcite. That again is only query, and no storage. It has a concept of 'adapters' which, I assume, is similar to the postgres-like foreign data wrappers you mention.
A similar situation was seen in India, when Uber entered the market. Most of the then-existing hail-taxi users were users of Ola (the home-grown service). Users here use both apps at the same time (comparing ride prices to make the choice). This meaning Uber and Ola eat into each other's revenues and markets across cities in India.
The short answer is I don't know. However, the convenience of simplifying the calculations is, in my opinion, a win. Again, I am myself not convinced. Probably, my premise on the ubiquitousness of normality assumption on the residuals in ARMA models is itself flawed.
I can relate to this. I grew up in India when India was a closed economy, with anything (commodities or services) either too expensive or limited by license raj. My father, being a lowly government official, did have a steady but meagre income. Groceries and mortgage were always on his mind. But, he also had his habit of never borrowing, in spite of dire need. Never kept a credit card either (to this day). I have learnt that brand of frugality from him.
not to mention, some awesome references at the end of each chapter. I had made it a point after each chapter to randomly pick an interesting reference and read that as well.
I have recently started organising little snippets of learning I gather during work using dnote (https://dnote.io/). For instance, I have organised multiple 'books' around topics such as regex, Apache Spark configurations and others. The best part is that it works right off the terminal. But as a downside, it is not the best way to take extensive notes; only 1-2 liners.