Even if OP is using 5.6 or previous, strict mode has been available as an option for over 15 years, and can be enabled dynamically (no restart required).
I simply don't see any valid argument for avoiding MySQL due to "data reliability" concerns in 2019.
> There were other minor deficiencies mentioned in Klepmann's book on Designing Data apps, but I don't remember the specifics now.
Well, I can't really respond to non-specific points from a book I haven't read. I'm happy to respond to any specifics re: data reliability concerns, if you want to cite them. FWIW, I have quite extensive expertise on the subject of massive-scale MySQL (16 years of MySQL use; led development of Facebook's internal DBaaS; rebuilt most of Tumblr's backend during its hockey-stick growth period).
