Learn English – Respectful Noun for Really Hard Worker

I'm reading Jon Gertner's The Idea Factory: Bell Labs and the Great Age of American Innovation.
In describing the history of the telephone, Gertner describes Thomas Edison (whose inventions helped improve transmitting voices) with:

Edison usually worked eighteen hours a day or longer, pushing for weeks on end, ignoring
family obligations, taking meals at his desk, refusing to pause for sleep or showers.

This perseverance reminded me of a personality in David Kushner's history of software company id in Masters of Doom.
It cites game engine designer John Carmack
as saying:

If you want to set off and go develop some grand new thing, you don't need millions of
dollars of capitalization. You need enough pizza and Diet Coke to stick in your
refrigerator, a cheap PC to work on, and the dedication to go through with it. We slept on
floors. We waded across rivers.

I recall the book also having an anecdote where Carmack's co-workers test his resolve.
They play a movie at high volume while Carmack is working.
After turning around briefly to see what's going on, Carmack continues his work as before.
And throughout the book Carmack puts that kind of effort into every project he attempts.

I would like a noun that captures more intensity than hard worker.
There are hard workers and then there are very devoted workers, who may agree with
Gustave Flaubert's quote:

L'homme n'est rien, l'oeuvre – tout [which translates to] The man is nothing, the work – all

At the same time I would like the noun to be respectful, if not praise the subject for their industry.
For this reason I'd like to avoid workaholic, which has a compulsory and involuntary aspect to it, as shown in this WebMD quote from Are You a Workaholic?:

But for workaholics, the day of rest never comes. There is always one more email to read,
one more phone call to take, one more critically important trip to the office that can't
wait until Monday.

Weekends? Holidays? Family? As the uber-workaholic Ebenezer Scrooge put it, "Bah, humbug!"

Similarly, busy bee is not serious enough for my situation.

The word I like most so far is workhorse, defined by MW to be:

a dependable person who does a lot of work

Unfortunately I am drawn to think of being overworked to the point of injury, such as Black Beauty, who "collapses from overwork," or Boxer in Animal Farm, who "[despite] his injuries… continues working harder and harder, until he collapses while working on the windmill."

Is there a complimentary, respectful, or more neutral noun to describe a really hard worker?