Well, since you haven't had a reply from Bass Central (I try to avoid posting in the sponsored forums unless the sponsors reply first), I'll say this.
I use open strings when necessary, but being mainly a fretless player, I rely on my technique and the wood of the fingerboard to make my notes speak. The sound of an open note is the instrument speaking; the sound of a stopped note is the sound of the musician speaking.
But add a brass nut if you like. It's 1/1,000 of what's important for your role as a bass player.
Tuning a mellotron doesn't. - Robert Fripp