> Hand-written parsers are even worse. Using an LR parser generator is worth the time investment.

I'm curious, what makes you say this? From what I've read online secondhand, people tend to recommend handwritten recursive descent parsing and Pratt/TDOP parsing, because it's easier to add good error messages and later add context sensitive productions (e.g. the way Clang resolves class-wide declarations while parsing C++: https://eli.thegreenplace.net/2012/07/05/how-clang-handles-t...).