Yes:

Claude 3.5 (either Haiku, Sonnet, or Opus) has at least one control vector enabled by default, where a "control vector" is the up-regulation of a specific feature's weights during inference. An example of this is "Golden Gate Claude," in which the Golden Gate Bridge feature's weights were up-regulated. The control vector must be added for the purpose improve its capabilities (or reliability) either generally or in specific domains. If a decision to dynamically enable the control vector is present (e.g., only enable if there is a coding task), this counts as being enabled by "default" unless it is only enabled very rarely, such that most users will not encounter it.

No:

All Claude 3.5 models do not have any control vectors enabled by default in the chat interface or API.

Does not resolve until there is decent evidence pointing one way or the other. In order to resolve yes, there must be a preponderance of the evidence (but not absolute certainty).