I noticed that tags/headers/etc. style names (and regexes) are hardcoded in the folding addons (xml - \btag\b, markdown - \bheader\b and function headerLevel - ^#+).
It would be nice if they could be parametrized (like for example config.bracketRegex in edit/matchbrackets) where it’s possible, for example for use with a custom mode/text that uses different naming convention.