Function source_line_payloads 

pub fn source_line_payloads(
    input: &str,
    format: Format,
    config: Option<&FormatConfig>,
) -> Vec<Option<String>>

Per-source-line prose payload from the same parse_full walk format uses.

None means the line has no prose rewrite range (structure, code, blank, pragma-off). Some is the original-source slice the parser sent to the splitter for that line (list/quote body, mid-line comment prefix). config supplies [latex] extras; None keeps the built-in lists.