Instructor training requires more breaks

As @konrad and I were teaching an instructor training last week, we received multiple requests of more breaks.
I completely support the idea. The sections are about 3.5 hours long, with only a 15-minute break in the middle. This is not enough. The instructor training itself reminds future instructors of the importance of breaks, and it feels like it's not practicing what it preaches.

No files or tests are named. Review the instructor-training sections and their documented timing, then determine where additional breaks should be represented; done means the schedule provides more breaks than the current single 15-minute break during each roughly 3.5-hour section.

Written by the indexing model from the issue text.