the only valid answer is
unless microsoft adds a toggle that stops all automates power controls(ie allows you to disable all automatic reboots for any reason, except actual BSOD issues not related to some critical process being in the pagefile despite it being stupid to not have a process blacklist for swapping)
install linux instead of windows
it might sound like I am some linux fanboy, nope
I just understand and accept that my computer should never do anything I do not tell it to do, which includes any time it leaves the s0 power state, for any reason other than loss of power(which may be outside of your control
yup, if my pc sleeps, reboots, shuts down, anything other than idle at desktop, it is 100% my choice, microsoft has no say in what it does
the only thing they can complain about is online services like onedrive
if I have my pc set up with a local account and no backup, it does not reboot, ever
now yeah, reboot when it makes sense, like when you are sitting there eating dinner and have some time to kill while the OS reboots to apply ONLY the kernel updates(because non-kernel = never reboot, figure it out or don't push those updates at all, take a page out of linux's book)
simply put, unless the only time my pc ever shows the bios splash screen is when I manually reboot, then uninstall windows, period