Author here. Seemed like the least bad of the options.
Being able to comment out sections of a config file easily is a prime use-case; and that really implies using newlines as delimiters, and well, you fall into this trap..
Why is the ability to comment-out entire sections of a config file a primary use case? What are the motivating requirements for this feature?
That aside, you don't need semantically-meaningful indentation to support commenting-out whole sections, see e.g. any braces-based lexer/parser that supports `/* ... */` style comments.
Being able to comment out sections of a config file easily is a prime use-case; and that really implies using newlines as delimiters, and well, you fall into this trap..