Did you check this: https://www.sagecity.com/support_communities/sage_erp_x3/f/sage-x3-general-discussion-forum/135252/purchase-request-auto-signature-how-to-stop-this/398631#398631

Cheers.

Yes, I was able to turn off the automatic signature for the situation that the buyer is the first person in the workflow. But, when the buyer is the second or third person in the workflow, the PO pushes back to the bottom of the workflow to signer 1 for approval, then goes through the rest of the levels, including the buyer for approval. I am trying to configure it so that the approval starts with the person who is the level above the buyer, and not start from the beginning of the workflow. 

OK. understand. I would create 4 different rules, and manage the conditions, not sure if you can do it without development.