Alright, I 100% cleared Octo Expansion. It is great, play it. The soundtrack is incredible, it's challenging but fair, the last boss is super silly and fun (and does not in any way involve DJ Octavio, it's a completely new character and battle), and Off The Hook and Captain Cuttlefish get a lot of fun characterization.
That's my main complaint about the whole experience honestly,
. Small issue though. Everything else is excellent.