This seems like it is the wrong solution for this problem. If the comma confuses the preset string parser, shouldn't we instead add support for escaping commas?

I use globs instead of regexes exactly to avoid double-escaping (one \ for escaping in regex, one \ for JSON, and you end up with something that's hard to read - and hard to write correctly for other team members).

Also, strictly speaking, such change won't be backwards-compatible.

{{args}} may still be valuable for varargs kinda references, but that's an entirely different usecase.

There's (currently) no way to generate a json array, not even talking about anything more complex. So varargs are pretty much useless. You can't even use arg* as a variable in handlebars.