Record Stabilizer on a Suspension Table?

I have a Thorens TD-166 MkII with original Thorens arm. Although I am not adding to my vinyl collection, I do want to enjoy the LPs I already own, and would like to digitize them as well. Since many of my LPs are older, I thought a stabilizer or weight might help get the best results. Although the table is not on a high quality rack, the rack itself sits on my cement basement floor, so vibration control is less an issue than flattening out warped LPs.

My question is: How much wieght can I add the platter without negative affects on the speed, suspension and bearings? I was thinking of an inexpensive clamp like the Souther.

Also, I saw one record clamp that although lightweight (3 oz.), cautioned that "consideration" must be made when using the clamp with suspension 'tables. Why would a 3 oz. clamp be a problem?

Thanks in advance!