Understanding and setting Betaflight rates & expo
Rates and expo don't set your tune, but they set your feel: how fast the quad rotates at maximum and how directly it reacts around center. They're the first step before PIDs even make sense.
What rates and expo do
Rates set the maximum rotation rate at full stick; expo softens the reaction around center without lowering the max rate. Together they define the setpoint — the target the quad should follow.
Rate types (Actual, Betaflight rates)
Betaflight offers several rate systems (e.g. Actual Rates, Betaflight Rates). Actual Rates are the most intuitive for many because you set the max rate directly in degrees per second. Pick one and get to know it instead of constantly switching.
Rates are taste, not tuning
There are no wrong rates — only ones that fit your style or don't. Freestyle often uses higher rates, cinematic lower. Change them independently of the PIDs; they fix neither oscillation nor heat.
Why rates matter for analysis
Because PIDoctor measures tracking as setpoint-versus-gyro, your rates are the starting point of the evaluation: they define the target your tune has to hit. If tracking is off, it's the PIDs/filters, not the rates.