How are loading times to be proven with this tachograph prior to departure?

Your answer is correct because, according to German traffic regulations for professional drivers, loading times before departure must be entered directly into the tachograph. This is necessary to have an official, tamper-proof record of these times as part of the driver's working hours. Simply noting loading times on separate paper or just informing the employer is not sufficient proof for the authorities. The tachograph system requires these times to be programmed into the device to ensure accurate monitoring and compliance with driving and rest time regulations. This helps to prevent unauthorized driving time and ensures safety on the road.