Before Naoki Maeda composed music for Dance Dance Revolution, he went by another identity, "Ensoniq Maeda", and composed music for other Konami games, such as Salamander 2.
Some of the BEMANI musicians play their own games, with varying degrees of success. REFLEC BEAT sound director DJ YOSHITAKA has shown himself to be able to play his own game very well, and DJ TOTTO is a Kaidennote highest dan rank-level beatmania IIDX player. Meanwhile, pop'n music sound director wac is somewhat notorious for his appearance at JAEPO 2013, where he shows that his pop'n abilities...have a lot of room for improvement. (To be fair, he did play Ongaku [EX], one of the hardest charts in the entire pop'n series.)
185 BPM is known by some as the "Yoshitaka constant" or variants thereof, due to DJ YOSHITAKA's strong tendency to use this speed in a large number of his songs.
In fact, it's such a prominent constant in his songs that people initially thought that Rche was DJ YOSHITAKA's alias simply because of the use of repetitive chords and its bpm.
"Soflan", a term used for sudden and dramatic BPM changes. The term originates from "SOFT LANDING ON THE BODY" from beatmania IIDX 2nd Style, which shuffles between 79, 159, and 318 BPM. Bonus points if the song itself does not actually change BPM but the scroll BPM does.