Interesting stuff.
When I bought my bass a year ago, it had a heavy steel end pin and I had it switched out for a carbon fiber. I also had them change the strings and a different tailpiece so I dunno what effect the lighter end pin made. Mainly, I wanted to lighten the load.
The bass sounds great with a big, resonant tone but it does lack that really centered powerful low end. That is, until I remove the rubber tip and stick the point in the floor. It's like the E string grows some cajones. I suppose I could try a 14mm steel rod but that would add a bit of weight.
Prolly should just learn that new tune for tomorrow's gig.