I do have one follow-up question though: I was under the impression that clock trees contain repeaters in the form of CMOS inverters. Wouldn't those have dynamic leakage which the transmission line stuff doesn't account for?
From my understanding: yes, the CMOS inverters will certainly use power. But you can minimize the use of them through some passive techniques.
Looking into the issue more, it does seem like a naive implementation of synchronized clocks can become costly. But at the same time, I'm seeing a number of research papers suggesting that people have been applying transmission-line techniques to the clock distribution problem.
I've always assumed that it was something that was commonly done at the chip level, but apparently not. These papers were published ~2010 or so.