Speaking of Kogoro's past, I remember the incident in the ship that got Heiji's attention participating, and so do Conan and others, it's like Heiji possibly lured to ship in case of murder may happen. I forgot who is the person go through all this, but it seems Kogoro has involve with B.O. in the past, as he was one of the officer who aim to catch the group.
If I remember, that incident is some kind of interlude, because before that interlude happen many years ago B.O. has one member murdered nearby the sea, he was drowned... No one ever knew did the person survive or not. The existence of B.O. was known to Kogoro in the past when he was working with ex-colleague, who once plan like Shinichi to take them down and don't know Shinichi was also deeply involved, and on that cruise where Heiji was lured to solve, Gosho has started go into depth introducing B.O. is the group Kogoro was responsible to catch them and serve justice.
I can guarantee on that cruise ship one of them is the boss because the ship is biggest important setting that no one can get in touch with them if they are in no man's island, B.O. member can use this as their advantage discussing as no one will thought of ship is the place B.O. members will talk about.
Secondly, another B.O. arc did happen around Halloween ghost ship, where Vodka was there with given invitation by Vermouth who is likely related to entertainment company who wants to find actor and actress for audition which hosted in ship. Since Vermouth is Vineyard, she can straightaway transfer her finance into second account, she can be counted as one of the riches in America.
And one thing about B.O. without Vermouth they can't do much because she has biggest influences to get time side with her, and likely the boss she get in touch with could be one of the stakeholder of one of the company as they has bigger influence over ship or parties to get their operation done with stealth and group.
If Moriarty is mastermind, he can host his own book signing event to show he is one of the greatest doctor and no one ever can suspect he's the boss who has lackey work for them. The boss' name may be indirectly mention in parties, or events hosted by him and artistes in entertainment and may participate because Chris is involved as prolific actress; he see no point sitting back if he can join in event and having fun without anyone suspecting he's the boss.