We haven't wired the BL Touch because we don't have the mount printed. Haven't even looked at the instructions, but from your comment it takes the place of the Z probe? That makes sense why it bounced around on its own, it did moved on to each position just after the Z stop clicked.

Anyway, no I don't really want to get crazy customizing my firmware - I don't even know what I'm doing - but the auto bed level doesn't look any better than the manual bed level, just more hassle, the manual was easy and quick to do. So I just want to do that. I assume this would require some change to the Z probe settings in the config file though, now that I see how the ABL is using it.