Acceptance Radius in Guided mode (Offboard)


I use a companion computer to control a quadcopter in Guided mode (Offboard control). I run the 1.9.0 rc1 px4 firmware.

The parameter Acceptance Radius when reaching a WayPoint is available for Mission Mode, but how to change it for guided mode ? What is the default value ? If not possible to change it by Mavlink command, where could I change this parameter in the source code ?

I use this for indoor autonomous application and I need to be able to reach at least 30 cm of acceptance Radius.