Yes, the Wireless PRO Receiver (RX) can now be used with TRRS microphones in Headset mode. This means that popular options like the SmartLav+ can be connected and used with the RX when the 3.5mm port is available.
We also have an article about Wireless PRO Headset mode here: How to use a Headset (TRRS) with the Wireless PRO.
For more information about the Wireless PRO, please see our Wireless PRO User Guide.