Thanks Keith. The official dark theme loads faster and is far smoother to use than our previous custom CSS, and now we see all the new animation and fade effects in full dark mode.
Might need to rework the dark theme css opacity for the INS logo though to swap when dark theme is turned on, its almost impossible to see now at the top of the page when official dark theme is on. Viewing with Opera (latest) browser.
The issue has been mentioned on meta.discourse here. The contrast of the topic title/header text seems just a tad dark on ours and the INS logo image you can hardly see.
See my screen grabs below.