Ok, I went to a talk about zephyr but it was actually guy wearing a suit talking about how he couldn't get his proprietary FPGA toolchain to work, commenting that he knew about the free toolchain - just he didn't want to use it. It was a bit of a let down and it feels like he maybe missed the audience profile. He also tried to plug some commercial offerings.
Anyway, now it's about kids designing and building airtag alternatives!