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.
If you have a TRS 3.5mm Lavalier microphone like the Lavalier II, use a TRS-TRRS adapter (e.g SC4) to connect it to the Wireless PRO RX.
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.