@Pallavi H P
No, activating the witness signing option does not impact the consumption of DocuSign envelopes in the way you're describing.
Each envelope in DocuSign represents a container for documents that are sent out for signing, regardless of the number of signers or witnesses involved. As long as the document is part of the same envelope, adding a witness will not cause it to consume additional envelopes.
In your case, whether the document is signed by one person or includes a witness, it will still count as one envelope since all signing actions occur within the same envelope.
This principle applies unless you're sending the document in multiple separate envelopes, in which case each envelope would be counted separately, but that isn't tied directly to adding a witness.