Thread:VisualEditor/Feedback/Tab doesn't even show up in Pale Moon, permanently loading (8+ hours) in Chrome and stock Firefox/reply (4)

(See my comment above re. Pale Moon.)

It's not clear to me what issues you were having with Chrome and Firefox being stuck on loading - are they still present? I cannot reproduce here on Mac, Linux or Windows. It could have been an issue with the Parsoid load-balancing infrastructure that has since been corrected.