If it spread to a become a defacto standard format, wouldn't that be a good thing? That way you only have to deal with this once and it will work everywhere.
At that time, the size/parse time will have much greater impact because the total size of libraries will be smaller or unaffected.
At the same time it encourages libraries to put significant error messages in their code without fear of bloat which helps your customers in the end.
Since the URL to the raw mapping is not in the error and requires external knowledge and the parameters are in free form in the error message I doubt this can become a standard of any sorts. The correct place for this would have been something like sourcemaps.
At that time, the size/parse time will have much greater impact because the total size of libraries will be smaller or unaffected.
At the same time it encourages libraries to put significant error messages in their code without fear of bloat which helps your customers in the end.
Personally, I hope everyone will follow.