Flight computer tells engine to go. Full go, launch sequence. Engine goes. To me, anything but that isn’t a full-duration anything.

If clamped down, it’s a full-duration static fire. If clamps release, it goes to space. Basically, if the engine can’t tell (apart from atmosphere, which is a big apart) it isn’t going to space, it’s a FDSF. It’s a whole-engine show. If you’re running parts through a full duty cycle, that can be done in a lab (or on a stand).