the thumbnails now are even more clearly 4-pixel potatoes

pictrs’s thumbnail parameter uses dumb raw pixel sampling – which leaves something to be desired… It has other sampling options implemented (with resize, according to the docs), but they don’t seem to accessible on my instance. You can remove thumbnail=96 if you want to get the image without that thumbnail sampling, at least.

make everything zoom 150%

I do this with my browser’s UI (ctrl-plus keyboard shortcut in FF-based browsers works for me).

e.g. right side bar

[…document.querySelectorAll(“.side”)].forEach(sidebar => sidebar.remove())

You could also just adblock the element with class side.