> it’s not a drive in that it’s not providing atypical propulsion (ie, Star Trek warp drives,

AIUI in Star Trek, Cochrane's "space warp generator" and descendants are essentially the Alcubierre design: I don't seem to understand that the warp bubble provides any propulsion by itself (although grav waves could be surfed)

Instead AIUI actual movement is created by a secondary mechanism, which I'm unclear about from a cursory search. Maybe impulse engines? Or maybe those are inefficient/incompatible with warp and it's using a secondary system that comes as a (intentional by design) byproduct of nacelles, like a ramjet engine airplane essentially has two propulsion systems since requires forward speed so you gotta have regular engines.