Tbh I don't think there is a definitive answer to your question, it's all about what feels right for you and your style of driving. Just try the buggy with and without the weights and see how it feels. Me and four mates run kf's and all our buggys are set differently, some have weights some don't some run shorty and some run saddles but were all getting around the same amount of laps. Hope this helps but I think trial and error is the way forward.
