I read that you wish to keep this app minimalistic, and as someone who shares the same philosophy, I can appreciate that.

I'm wondering if adding linearization of PDF files (so that meta data is actually removed), would be within that scope, or overkill?

Here, someone is using QPDF to compliment ExifTool to accomplish that:

https://blog.joshlemon.com.au/protecting-your-pdf-files-and-metadata/