If there is indeed an "order of operations" as nostr:nprofile1qqsywt6ypu57lxtwj2scdwxnyrl3sry9typcstje65x7rw9a2e5nq8sprpmhxue69uhhyetvv9ujuumwdae8gtnnda3kjctvqydhwumn8ghj7un9d3shjtnzd96xxmmfdecxzunt9e3k7mgpp4mhxue69uhkummn9ekx7mq9hxafw often says, then it would seem to make sense for all spending wallets to ask users to choose their (current) Unit of Account as part of the onboarding flow.

Sure, sats can be one of the choices for the hardcore bitcoiners that already denominate their lives in BTC. But for MASS adoption, don't make users think in a new currency. At least not yet.