First of all, I would like to thank you very much for all your suggestions. I have a feeling that it might be difficult to further reduce the sampling time with the Arduino IDE. As an aside, I have also identified another problem and have already pointed it out in a separate forum post (Connection Pixhawk 4 with openManipulator). Perhaps there is a way to address and solve both challenges at the same time. If you also have ideas or approaches to solving the other problem, I would appreciate your suggestions.