Finally saw this. My internet's been out since last Tuesday, and I'm catching up now that it's fixed. (Apparently some wires got crossed at the switching station where my phone line ends up.)
This has been a mediocre season, and the finale didn't do much better. There were some real howlers, like the idea of a satellite having the power to drain the Sun, not to mention "knock the Sun out of orbit," which implies the writers were unaware of the past 500 years of scientific progress (2500 if you count the Greeks) and assume the Sun orbits the Earth. The bit about Supergirl inspiring the people with a speech was a blatant copy of the first-season finale, and didn't work remotely as well, because the situation was just so cartoonish and silly. The whole totem business never made a lick of sense.
Aside from the inanity of the plot, there were some worthwhile character beats. Bringing Lillian back and giving her closure with Lena was appreciated. I'm also grateful that they managed to bring back Cat for one final inspirational exchange with Kara, despite having to do it over the phone. And it was nice to reunite the OG Superfriends one last time and have them reminisce on how it started. Although it felt like too little, too late for them and Cat, since we've seen them so rarely.
I feel sad that Nyxly ended up trapped back in the Phantom Zone. I think that's cruel and undeserved, since it was an injustice that she was imprisoned there in the first place. It would've been better if they'd found some more humane resolution for her, or even redeemed her. She had potential for redemption, particularly in her compassion for Esme, and it's a shame that potential was wasted.
So "We Belong" is a Pat Benatar song? Okay. For me it was just one of the more agreeable of the oldies that played constantly on the PA at the university bookstore where I worked for about a year back in the '00s. I always rather liked the refrain, though I didn't know who the singer was. Benoist and Jordan sang it very well, though I missed the strong, heartbeat-ish percussion line that's part of what makes the refrain so striking.
Calista likely shot all her scenes in LA.
There was indeed a "Los Angeles Unit" credit in the end titles, but only a couple of people were credited as part of that unit, about what you'd expect for filming inserts of one actress on what was obviously a greenscreen stage.