The first wave of the CH1 waveform seemed to have a tad higher voltage peak than the rest of the waves, so a possible 4th way to avoid major jitter could possibly be to increase the trigger level to just below 2.39 volts (4.78 Vpp/2).
This could be a solution if you use an old, analog scope without high tek standoff, pulsewidth stuff or if there were no sync pulse available.