As I see, there is no hint in the manual that the LFO may be re-triggered by keypress, so I guess it's simply free running (= started when you turn on the synthesizer). As velocity and aftertouch were added for additional expression/control, can we expect an keytriggered LFO option as well?
Idea would be to press and hold a special button like velocity or aftertouch for more than 2 seconds to engage or disengage keytrigger. This would be great.