So, while I think it's plausible to say that final gate doesn't worry about the "same trigger" restriction, the fact that the first action you take in the round has to be final gate suggests to me that by the time you get around to having finished final gate's action, you've already missed the trigger for Effortless Impulse. Which is super lame, because that means Effortless Impulse is kind of garbage at 19th level unless you used a sustain impulse that isn't Overflow (so, Ignite the Sun).
So even if Final Gate isn't the same trigger, the particulars of final gate prevent you from using it with start of round free action effects.
