What from Earth-66 also takes place on Earth-76?
Edit: Or is it just like Doom Patrol and Titans were Doom Patrol are both on Earth-9 and 21 but the show only takes place on Earth-21?
I looked out for that while reading but all the ones that stood out to me were easter eggs to the comics, for example Superman in a black suit or Lex with a ginger beard and mullet.
Keep it in Earth-76. I don't think they have intentions of changing Earths with other DC shows and movie on as Marc Guggenheim said "I promised that I would put all of the toys back in the toy box once we were finished".
Something that has confused me about 60's Batman, in 1977 Dick has become Nightwing but in 1979 he is still Robin. The rule normally with canonicity is if it's on screen it's canon, so is this evidence towards the tie-in comics not being canon