The esoteric part is the combination of "Setting preferred fonts for generic font families" AND the security adjustments necessary to trigger "Request for font XYZ blocked at visibility level 2"

Sure if you want to set browser prefs for fonts, go for it. It'll make the OG sites with almost no stylesheet a little more readable (looking at you, wiki.c2.com). But you should not expect or ask web page authors to not use their preferred fonts. If you want to override web page fonts, use a more invasive or pervasive tool.

Font/page size preferences, on the other hand, web page authors should respect and do a better job with.