Juste put hekate.bin into atmosphere folder and rename it reboot_payload.bin
He wants to make it so that stock firmware has that functionality because he frequently switches between OFW and CFW. This is impossible without running CFW on SysNAND, which breaks Nintendo's Terms of Service. So if he sends it to Nintendo, they can, if they see that he ever ran unsigned code, refuse to fix any problems it has, so even if he would ever wish to give up on CFW on that Switch just to fix it (Nintendo would patch RCM at the repair center), he would be unable to. It's not worth it. Just buy an RCM dongle and call it a day.
Edit: The Switch has a TON of telemetry. Atmosphere's module replacements remove all of it, but stock with only the reboot to payload feature will not do so.