There's such a thing as too much metal for any acoustic based instrument, like heavy metal bridges and metal nuts.
But if you're attenuating to compensate for signal loss because of effect compilation, the "ping" you make is an easy mid mix.
That's still troublesome onstage, especially if the other musicians want to hear tone while they're playing.
Even luthiers I know say cutting a fret isn't a sure thing, making two or three to get a good one. I'm the same.
It's easy to place a piece of something under the nut to lift it up, so you can cut your even slots to match the low one,
and keep doing that until you've got a good one. Or you can start over and just get a nut that works without shims.
That's hard enough to do with bone and ivory. Metal is almost impossible, by hand.
A height adjustable nut doesn't sound practical to me.