You are correct, they are a starting point, anyone doing serious corner weights would have scales for their car. But it will take out the spring height guessing assuming you are going with the 435/355 shocks. As the OP didn’t post their weight the rest of the calculations are never going to be better than front to rear.
the rear shock will be the one to watch out for, as no one has built a 3rd party shock for the Tesla and having a shorter closed length on the rear will result in wishbone/chassis damage as the rear weight will overpower what’s already on the market.