I would suggest supporting the Test Anything Protocol (AKA "TAP") as a format.
It's used by a bunch of smaller specialty linters and testers like bash, perl, and fish.
There is a standalone TAP plugin but it would make sense to add it into WNG.
Are you planning to add that format on your own? Typically parsers are provided by volunteers who use those tools on their own.
New parsers are provided by volunteers. So if someone provides a PR I would be happy to integrate it. An issue is not required for such tasks.