Explained here:
https://www.altbierbude.de/images/events/2023/
60s_2023/Reglement_60s_Cup_2023.pdf
For the weight penalties of the Top 10 you have to look at the left/German side though, weight loss is correctly explained on both sides.
And with that I hope next 60s Cup losing weight is once again done based on position instead of laps, since the scoring is based on position and losing a lap doesn't necessarily mean losing a single point, but can make you be 40kg lighter next race (next to the difference in lap length making it easier to lose weight on shorter tracks like Barbagallo).