Add option to always open PDF files in a local PDF viewer application

PDF files are viewed with PDF.js these days, but,

1. That doesn't always work (see attached screenshot persisting for at least a year); and
2. I'd much rather open PDFs with evince (or whatever the system PDF viewer is) anyway, to avoid a whole bunch of unnecessary performance and security issues.

I see in the source code that there's a special PDF handler enabled to make all of this happen. Would it be possible to add an option allowing the user to disable it? So that PDFs are treated like any other downloadable file type?