I wrote a configuration language for CTOS back in the day. It ran on a multi-processor box and was responsible for launching services in a coordinated fashion across the processors during boot.

Instead of a language, it was a schema for configuration statements. You edited the schema to add new launch commands, then added launch commands to the script.

It was pretty esoteric - used all three kinds of braces to express one-of, required, optional etc. The only person I knew who changed it other than me was Andrew Thurber (the one at Cisco). He was a new hire at the time, and I was startled to find he'd just read the schema-parser code and figured it out.

Anyway not sure how that approach fits into the OP's objections.