My favorite of his operas is the Golden Cockerel. So evocative and you can really see how influential the French had become to the Russians at this time and how Stravinsky would almost immediately take the reigns from where Rimsky-Kosakov left off with The Firebird.
This is the CD release I have of the complete opera
https://www.youtube.com/watch?v=AJnAkpqVDcc
But I also enjoy the very fine suite as well.
https://www.youtube.com/watch?v=UbW12kX6kEQ
I only know the suite, which is very evocative indeed and quite forward-looking. It definitely shows a more advanced approach to harmony than his more famous earlier works and you’re quite right about it “paving the way” for
The Firebird.