[read the thread]
IMO, just use one single `#` as you did at the start, and don't worry about the `comment_use_indent` comment ~~comment comment~~ (oops, got carried away :upside_down_face:). * `# ` as documentation comments in conffiles is most common * `#key=value` as commented-out default/suggestion is common (many things in e.g. /etc do this) * `## ` is a *lot* less common, so is `#~ ` indeed.
The one thing you possibly could do is still add a leading `#` to the `\t#comment` line, e.g. "if line is an indented comment, add a documentation comment prefix", but that might be an overly specific case to warrant it, and special cases have a tendency to come back to bite you…
and language-specific config files would contain only those values they override to some other value than `filetypes.common`
Hum, I'm not sure it's a great idea. Some settings make sense to be modified per-filetype rather than necessarily globally, and I think those are the ones showing up in filetypes definitions. E.g. `comment_use_indent`: it's both a user preference, but also not all languages are happy about it, or their canonical style isn't. Similarly, `wordchars` has some use per-filetype, where identifiers are not limited to the usual (say, they contain `-` for example). So yeah, there surely is room for improvement, but I don't think going whole "no non-overriden settings can ever be mentioned in filetype definitions" is the best move.