I personally do not understand the buzz around constexpr etc. All the real buziness is happening at runtime anyway and compilers already optimize code quite decently. The extra maintenance burden just doesn't pays off.
I think you should review his premise: he is using constexpr to eliminate a separate exe, a data file, and code that loads and reads the data file at runtime. His maintenance burden goes down.
It's like 'const' itself -- it's a tool for producing better error messages, not better final executables.