> am I correct assuming you pretty much give up the benefits of a readable grammar as documentation?

This is more of a question language than a parser language. If you have a language that requires a Turing-complete parser than you gave up on grammar. You can use Pratt to parse languages that have grammars.

The language that I'm implementing has procedural macros (hence the parser is Turing-complete). However it has some "structure" that I can port to a tree-sitter parser. The tree-sitter parser for my language won't be 100% accurate, but it'll capture the most important structures.