Ah, gotcha. I was focused on my use case of static text.
If your charting library runs server-side and outputs HTML/CSS, then it'd work fine, but most of that stuff requires javascript, and yeah, WeasyPrint doesn't have an interpreter. Once you're already paying the overhead of a browser, you're probably better off using a JS polyfill than piping through another tool, unless paged.js is an insane resource hog (which seems unlikely).
If your charting library runs server-side and outputs HTML/CSS, then it'd work fine, but most of that stuff requires javascript, and yeah, WeasyPrint doesn't have an interpreter. Once you're already paying the overhead of a browser, you're probably better off using a JS polyfill than piping through another tool, unless paged.js is an insane resource hog (which seems unlikely).