Frankly, the 250 and 500 settings do nothing for me, but Jack doesn't use them either. They might be interesting for people that want to drive their extreme effects with a beefed up signal, other than that it is hard to see what there is to like about sounds that take all the nuances out of this nuanced bass.
The original Gibson Les Paul Signatue had a second output at the side for "studio work" - I believe that was for the unadulterated low impedance signal to be fed into a mixing console etc. It was much quieter than anything that came out of the front jack irrespective of setting, in fact whatever the setting of the chicken head switch, its sound was unchanged.
The big dif between the Epi and the Gibson is that the latter regularly had a maple neck as opposed to a maho one. That makes all the difference in the attack of the thing, the Gibson is much snappier, unusually snappy for a hollow-body. But seeing how Jack plays, I believe he cares neither for snappiness or attack, but purity of tone and a certain mellowness. Which is ok, but the Epi has none of the Gibson LP Sig's P-Bass-bullish assertiveness.
I actually like the way JC promotes that bass, very understated, matter of fact. He also plays them off the rack from Epi, no fancy pants custom shop model for him. And it's nice that it is still in Epi's model line after all these years and that you actually see it quite a bit with pro players for an Epi (even if in the upper price range as Epis go). Is it versatile in sound? Not really. But players looking for a hollow-body are all about vibes and not versatility. It plays nice too.