A user's Limit Ad Tracking preference is passed through from Branch to ad networks. The ad network can then decide whether or not to target the user. The value of the flag does not explicitly affect attribution.
Having said that, when limit ad tracking is enabled on iOS, no IDFA is made available on the device. This means that for iOS users with limit ad tracking enabled, Branch will not make calls to self-attributing networks (e.g. Twitter, Facebook, Google, Snap) using the IDFA. However, Branch will use IDFV instead when available.
For more privacy tools, including the ability to opt users out of Branch attribution, please visit our docs page on SDK Privacy Controls.