Hi!
First of all, thank you for this graet addon!!
could you support BIMI icon (instead/with ?) favicon from numerous websites ?

This is, nowdays, part of dmarc/dkim standart https://bimigroup.org/ and in my opinion, be much more simplier to handle than your long list of favicons embeded with this (great) pluggin.

A dns lookup to default._bimi.domainname.tld TXT gave you an SVG file url (witch must be less than 10Kb if i remember correctly and of type tiny-svg), then give it to thunderbird instead of favicon ; thunderbird should be abble to render svg files on the fly.

Thanks.