Thank you, I'm glad you're enjoying the story. You're quite right, you do refer to JG's and Lieutenant Commanders by their core rank or simply as Mr. or Ms. I use the full rank partly as a character quirk of Kuznetsov's, but also as a tool to remind older readers and inform new readers as to the rank of a given character.
Again, I'm glad you're enjoying the story.
And, probably in the Russian navy, officers are addressed by their full rank. Of course, the Russians invented the navy . . .
(Sound of Pavel Chekov's voice, "Of course we inwented it!)