The primary difference between a DeviceRequest and SupplyRequest appears to be the allocation of a patient as the subject (required) to DeviceRequest while this is absent for SupplyRequest. Rather than having two like resources, but for that difference, having SupplyRequest support both (by adding SupplyRequest.subject) would support similar use cases. Proposal is to remove DeviceRequest. See other gForge for adding SupplyReuqest.subject.