I believe Vader was always on the same ship as the person he choked, so that could just be Long or Extreme range or some such. The comm giving him clear line of sight.
The other question I find myself asking is if I'd ever let a PC have such an ability or if that's in the firm purview of 'Sith lords.' As long as it's not a PC ability, I don't need hard rules for it as this is very much a design for intent system rather than stressing about NPC's=PC's.
Edited by Prost