Are only aoutbound mipr prs sps prs and dmlss prs subject to approval workflow?

No, not only outbound MIPR PRs, SPS PRs, and DMLSS PRs are subject to approval workflows. Various types of purchase requests can also require approval workflows depending on the specific regulations and organizational policies in place. Each type of request may have different approval processes based on factors like funding source, urgency, and project scope.