Following up from T178665, please update puppeteer rules for proton servers to match the best font config for PDF rendering.
I made all necessary changes bu running dpkg-reconfigure fontconfig-config and then selecting:
- Font tuning method for screen: None
- Automatic font hinting style: Medium
- Enable subpixel rendering for screen: always
- Enable bitmapped fonts by default: No (this config doesn't matter as it does not affect the generated PDF's)