I believe the big guy had everything in the OBEL, except the tuner.
From a theoretical aspect, the only one that really, really benefits from the OBEL is the envelope filter, though the octave divider may as well.
If you like being able to affect the sound of a distortion pedal, put it after the volume knob. It's really all up to you.
"Learn as if you were to live forever; live as if you were to die tomorrow."