That's certainly possible -- in fact, when I took the scope out of XY mode, it was already set up with the display triggering from the X channel input. In this view, the channel X waveform appears rock-solid dead-still, whereas the Y channel waveform shakes back and forth a fair amount as it very gradually drifts one way or the other. This is a little surprising, since the Y channel input is from a Siglent SDG2042X generator. I assume the jiggle doesn't necessarily mean that the generator's signal is unstable, but maybe it appears to be in relation to the X channel signal -- which could mean that it's actually the X channel signal that is wobbly (this being RF transmitted at a distance).
Overall I can't honestly say which view makes it easier to zero-beat the signals as quickly as possible. I think my advisor just likes working with the Lissajous pattern, but is used to seeing it render more smoothly.