David
I use a heavy Audiolife sub-platter on my SP-10 Mk2 with a heavy brass record clamp. I have also used an AT-666 sub platter as well but the 5Kg Audioplatter fits and gives the SP-10 better grip and micro-dynamics to the point where I can say the performance is comparable to my Micro-Seki RX5000 - comparable, not necessarily the same. The torque on the SP-10 is so great that the start up time is still fast. I don't think there will be any issue with the bearing as the extra weight will not stress the lateral forces.
I use a heavy Audiolife sub-platter on my SP-10 Mk2 with a heavy brass record clamp. I have also used an AT-666 sub platter as well but the 5Kg Audioplatter fits and gives the SP-10 better grip and micro-dynamics to the point where I can say the performance is comparable to my Micro-Seki RX5000 - comparable, not necessarily the same. The torque on the SP-10 is so great that the start up time is still fast. I don't think there will be any issue with the bearing as the extra weight will not stress the lateral forces.