The Rhythm one baffled me as well. I've been coding for 15 years and this bullet was one I couldn't find something to relate to or guess at its meaning.
Maybe it was more of a business aspect/market timing for a new product?
The way I interpret this is: when you work at a company with a fair size, you have to work with the release schedule of the whole company. If you have a large change you want to push (such as a breaking change in a widely used internal library), timing is very important.
You will sometimes need to work very fast in order to push your change while everything else does not change much. In these cases, it's important to be able to enter crunch mode, and it's equally important to alternate crunch modes with slower paced work to not burn out.
Maybe it was more of a business aspect/market timing for a new product?