Can Lyra series modules support BLE Mesh

The Silabs chipset from which Lyra series are designed (EFR32BGXX) does indeed support BLE Mesh protocol. However, Ezurio (formerly Laird Connectivity) AT Interface firmware doesn't expose BLE Mesh functionality. To get access to this protocol, you'll need to develop your own C code application through Simplicity Studio. You may find the following link useful for developing your own C code application: