How Do I Read the Performance Details in Performance Analyzer?

I often turn to the performance analyzer/performance details modal when trying to determine the root cause of slow sync times, however, I’m rarely ever able to glean anything from it. I haven’t been able to find any in-depth documentation or office hour videos that explain in detail how to read the performance details, does this exist and I’ve missed it? If it doesn’t exist, where would i submit my request?