Independence on internal audit engagements is more restrictive than on SOC work and more restrictive than most capacity conversations assume. The restriction operates on your firm, in relation to your client, and it is not something our involvement changes in either direction.
What our involvement does change is the supervision requirement. Work performed by people outside your firm still has to be directed, supervised, and reviewed by your firm, and the file has to show that it was. We build the documentation trail that makes your supervision evidenceable rather than asserted.
We would rather have this conversation at the scoping call than have your findings set aside later on independence grounds by an external auditor, a regulator, or opposing counsel.