I am wondering whether those with tone-arms which are secured by a ring-nut under the armboard (rather than 3 screws or bolts) have ever tried fitting a large (and heavy) ring-nut rather than the one supplied by the mfr?
I ask because I have a Magnepan Unitrac and the only upgrade-tweak I have come across (apart from changing the internal wiring - which is not a simple job) is to replace the slim fixing nut provided by Magnepan with the biggest - and heaviest - brass nut you can find! Which is a simple job! 
Andy