>     But it turns out that there are five (5) additional even heavier isotopes, each with an increasing number of protons.

As someone else said, I think you mean neutrons here, not protons...

>     I can’t see a place or role for superheavy hydrogen isotopes …

Veryhardtoobtainium? :-)
Something to do with Bose-Einstein condensates?
Anything can be a MacGuffin, of course.

>     I'm willing to leave the word as-is, but if someone can come up
>     with a different word, even a neologism, that better captures the
>     generalized meaning, without relying on the Greek root _anthropos_, which
>     technically means "man" (and excludes "woman"), I'd be appreciative.

Sophontomorphize, but IMHO, methinks you do protest too much.

Jonathan