Well, you can trust me when I say that metronomes inside software programs definitely usually aren't recorded, just like your metronome inside your SP-555 that's ticking but never gets recorded when only using the SP-555.
Of course, when you're recording all the output of the SP-555, you'll record the metronome too, but if you switch the metronome off on the SP-555 and the metronome of Ableton on, it shouldn't record Ableton's metronome.
But I'm sorry if I've misunderstood something.
you hear the metronome through your speakers, just as you hear it in the 555. its like cable going from your speakers back into the 555 so theres no way the metronome would ever be separate unless you turned off the monitor completely for the program
The metronome is on an internal track when it comes to both the SPs and software, it's just that the out going single has both the metronome and what you have recorded going to one and the same audio soundcard. Internally most DAWs won't ever record their internal metronome.