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Staggered generally adds understeer... so far I've seen no good (objective) reason to go staggered and several reasons not to on the model 3. If you're doing it for looks that's a different thing.
Finally made my decision. Went with 19" VMR V710 gunmetal. Decent price ($1070 before tax), local to me so I can pickup and relatively light at 24.5 lbs and super nice looking. They modify the rims in house to perfectly fit your car and seemed to be familiar with model 3s.
As far as track use, the choice of tire will make much more difference than the weight of the wheel, especially with something with as much torque as a Tesla.
With real racing, where the winner gets paid huge sums of money, a lighter weight wheel can be justified. For a typical club track day it would be difficult to justify.
High end, lightweight wheels will also give a certain amount of street cred. Nothing makes quite as much visual improvement as a nice set of rims.