I'd also recommend "Scientific Babel How Science Was Done Before and After Global English" by Michael D. Gordin [0]. It goes into detail about which languages scientists have used over time.
Mnesia is _not_ the storage layer for messages (except for delayed messages).
Mnesia stores vhosts, users, permissions, queue definitions and more. This is being transitioned to Khepri, which improves a lot of things (maybe most importantly netsplits) but not directly message speeds.
[0] https://press.uchicago.edu/ucp/books/book/chicago/S/bo145049...