Yes, I did the Turbo601/66 chipping project and the article on Schrier's page. I sold the thing some years ago and bought a refurbished Power Computing Power 120 with the proceeds (and some extra cash).
The Turbo601 is like a dancing bear. It's really cool that it dances at all, but it doesn't dance all that well. I decided that the Turbo040 is as far as I'll ever take my IIci.
That said, I think that the answer to your question is yes, but I did not do a circuit analysis when I performed the modification. That was before my EE degree, and I was a fair hand with a soldering pencil, but not all that knowledgeable.
I just compared the Turbo601/100 to the Turbo601/66 and made the changes in the 66 to make it just like the 100. So I documented which resistors needed changing, but I don't know what those resistors actually did. And it's way too late to find out now.
At the time, I didn't even know that the ICS9178 was a clock buffer, nor what purpose a clock buffer serves in a computer system.