I got the metal fingerboard working. The extra thickness puts the strings closer to the neck, so the strings were pinging the fingerboard.
I checked the neck with a carpenter’s square and found it convex. So I turned the truss rod to get it flatter. I used to always view that as a way to potentially ruin your guitar, but it’s OK to ruin this guitar, so it wasn’t nerve wracking.
Then, I raised the bridge. I think there is still some pinging in some places on the G string. But oddly, the ping doesn’t get amplified, so I decided to live with it.
I think it does yield a more ringing tone, but admittedly, it might not pass a blind taste test. Still, it’s neutral at worst. By my low standards for guitar construction, that is a victory.