As Chief Financial Officer for CFAR, I can say all the following with some authority:

CFAR used donated funds to pay for Yudkowsky's time in writing HPMoR.

Absolutely false. To my knowledge we have never paid Eliezer anything. Our records indicate that he has never been an employee or contractor for us, and that matches my memory. I don't know for sure how he earned a living while writing HPMOR, but at a guess it was as an employed researcher for MIRI.

It is my understanding also that Yudkowsky is working on a rationality textbook for release by CFAR (not the sequences which was released by MIRI).

I'm not aware of whether Eliezer is writing a rationality textbook. If he is, it's definitely not with any agreement on CFAR's part to release it, and we're definitely not paying him right now whether he's working on a textbook or not.

And given that further donations to CFAR are likely to pay for the completion of this work…

Not a single penny of CFAR donations go into paying Eliezer.

I cannot with authority promise that will never happen. I want to be clear that I'm making no such promise on CFAR's behalf.

But we have no plans to pay him for anything to the best of my knowledge as the person in charge of CFAR's books and financial matters.