I asked my SA about this on Friday. Once a VIN is assigned, you can ask to delay it. They will the assign another VIN sometime after this and you can cancel one more time. But the third time you get a VIN, you have to take it or forfeit your deposit and reorder. Here’s the real problem. He told me they are ramping up production so quickly that the second VIN might be assigned within a week of refusing your first VIN. And your third VIN might get assigned quickly too.
This was from an SA, so things might change or be different in your market.
If you’re waiting for new batteries in the LR version, good luck. They may never have the new batteries. The CT will probably get all they can make. There will always be upgrades, so when you do pull the trigger, a week later it may come with FLUX capacitors. You can’t beat Tesla at their upgrade game.