A catalyst 3850 supports all functions of a SG350 in terms of QoS. So, they should be ok. We also have other customers using 3850. In addition, certain models of 3850 also are PTP-aware switches which greatly help the stability of a PTP network.
With only a few IPT transceivers, PTP advanced functions are not required. Clear-Com recommends PTP-aware switches when deploying over 20 PTP endpoints (Iris + IPT transceivers in total) or when the network topology involves more hops (>3) between the E-IPA and IPTs.
These requirements however assume that Clear-Com traffic is “alone” on these switches. If the customer has other types of traffic (video, Dante, etc) and multiple trunking ports (i.e. multiple traffic types mixing into a trunk port even if they are using separate VLANs), it might require more attention. In case of doubt and if the switches are not already bought, using a network comprised of 3850 with PTP-aware function would remove the risk.