Yocto? Nobody is expecting Yocto for deeply embedded systems likely to be built on this OS. It’s closer to FreeRTOS, Zephyr, Embassy, but with this additional hardware-level safety guarantees.

My Yocto point might be colored by my experience of having seen multiple teams stick with Yocto beyond (IMHO) the point of pain and reason due to familiarity and industry inertia.