With the standard STCL-153P Sunnata dimmer in a three way it can only work with a mech switch at the other wallbox. We wouldn't recommend to use a mech switch with a locator light as it might cause functionality issues with the STCL-153P and if you are controlling LEDs as well. However near the end of January 2022 the Sunnata PRO ST-PRO-N dimmer will be released. It can work with the companion dimmer ST-RD. Here is the link to the ST-PRO-N support site page @
https://www.lutron.com/en-us/pages/s...RO-N&gqid=4323. If you have any other questions our tech support team is available at (1-888-588-7661) and
support@lutron.com