A chronograph is any watch with a stopwatch complication. I'm really not sure what your concern with a lever escapement is, as this is used on almost all mechanical watches.
I never heard that a stopwatch makes a watch a chronometer. That sounds like a marketing gimmick.
It does not imply a particular kind of escapement.
I have a Certina with ETA 2824-II and a Longines with ETA 2892-A2 which are inside COSC specs but not certified as chronometers.