I don’t want my spine hairs to be raised even more so I looked more into Linux than this other OS. There is something relatively new in Linux called “io_uring”[1]. I think this might be what you are looking for. The issue with this with respect to FreeRTOS might be how useful it can be on small Embedded systems and how much impact it can have on determinism of the system. Certainly it should improve the overall I/O throughput.