[jonmccull]

Vivaldi has a setting for limiting the minimum font size under Settings > Webpages > Fonts (screenshot: https://cl.ly/1h2N0Y3a3w0s).

Is that what you mean? You can set the font to max 24pt (on macOS anyway) and images are untouched.

[pvdebbe]

Yes, but site specific and so that I can adjust it on the fly. Sometimes I read in poor light and posture, needing larger text, sometimes I go for default sizes. Just like scaling on the fly but for the minimum font size. It's like Firefox is able to operate... for now.