useUpgradedAuth

Governs the credential arm of the kit's internal simulations and of the OZTransactionOperations.fundWallet source-account conversion.

When true, simulations request Protocol-27 ADDRESS_V2 entries and the funding conversion produces ADDRESS_V2 credentials, whose signed preimage (ENVELOPE_TYPE_SOROBAN_AUTHORIZATION_WITH_ADDRESS) carries the temporary account address. When false, simulations request legacy entries and the conversion produces legacy ADDRESS credentials with the non-address-bound preimage, for relayer services that cannot parse Protocol-27 auth XDR.

This is separate from useUpgradedAuthForWalletSigners: that flag serves wallet software that signs a preimage, this one serves services that parse the submitted auth XDR.