It's interesting to think that adding mass, using an inelastic belt, and increasing the contact area between belt and platter on a belt drive table seems (based on written descriptions of the results) to take the sound closer to that of the best idler drive tt's, none of which have particularly massive platters but most or all of which are profoundly benefited by a high mass, coupled plinth. I would wager that if one were to get belt and idler drive tt's that had been so modified into the same system we would find that they sound very much alike, as well as very good. Most of these insights come from the experimentation of skilled amateurs and reportage made possible by the internet.
Pedrillo, 30 years ago I had a friend who suspended his tt from his ceiling via very long springs. I think the suspension must have been underdamped, but the sound with relatively inexpensive gear was excellent.