It's not Toki Pona, but in some ways this effort out-ponas TP. Pona? “The Edge of the Sky is an enthralling read that turns on its head the conventional (and in my view thoroughly misguided) wisdom that complicated scientific ideas can only be described using complicated language. Roberto Trotta takes the reader on a fascinating and entertaining journey through the very latest discoveries in astrophysics and cosmology, using only the 1000 most common English words, but never compromising on the clarity and detail of his scientific descriptions. The Edge of the Sky captures with child-like wonder the mysteries of the cosmos in language accessible to everyone, making it eminently suitable for children of all ages!” –Martin Hendry, Professor of Astrophysics, University of Glasgow Amazon: The Edge of the Sky: All You Need to Know About the All-There-Is An interview with the author starts at about 13:49, Nature Magazine Podcast
that sounds allot like the Basic English idea. There's a core of 850 words, and they might add some specific words for a topic and make the number 1000. Someone made a Bible translation with this.
I thought so, too, except I can't think of anything compelling in book form written in Basic English that has the enthusiastic endorsements of so many persons with interesting curricula vitarum.