(I'm quite late on reporting this incident from over 2 years ago, but just spotted it).
In Sept 2019, four hikers were on the 2nd day of a 5 day hike in Wollemi National Park, New South Wales, Australia, when one fell and sustained multiple fractures.
They used a PLB to call for help, and a signal mirror to help the responding plane to pinpoint them.
The full story is here, 2nd column, 2nd story from top:
https://aiea.org.au/kinetic-technology-international-pty-ltd-1507767692811468/The signal mirror part is in this section:
"I checked the time after activating the PLB and it was about 10.05am. Help Arrives: At about 1:30pm a fixed wing plane arrived in the area and began to circle.
We used the signal mirror provided with the PLB and a small smoke fire to attempt to signal our precise location. Shortly after the plane left a rescue helicopter arrived at our location. I check my watch and it was 2:05pm."