New Customer Confusion

I'm a new customer planning to open a Beyond 2.0 family plan and pre-order/finance 4 iPhone Duos on the 16th, trading in 4 iPhone 14 Pros. Reps have offered me a 20% family & friends discount on the monthly plan, but I've heard pre-ordering through the Apple Store app gives the best shot at getting phones on launch day. Opening the account in the app would mean losing the discount. My options: Open the account with a rep (get the 20% F&F discount), then pre-order via the Apple Store app as a "new line" (potentially not getting the new customer promotions). Pre-order, open the account via Apple Store Checkout, and claim promos after (loosing the F&F discount, but potentially getting the new customer promos). Open the account on pre-order day and order through T-Mobile directly (thus getting the F&F and new customer promo). Questions: If I go with option 1, do I still get new customer promos (in addition to the F&F discount) on the new lines? Is the "14 days to claim new customer promos" I was told by a rep actually true? *Which route would you take?