jftr, you can also do it through a configuration file, but then it needs to have the variable in it (man live-config documentats that pretty good i think).
Well, actually my confusion was because I mixed up with all the different man pages and finding out at which point to look into which man page and which files they actually describe. Mostly reading the scripts help but it's very time consuming to understand your complex code as it's quite widely scattered/outsourced.
I admit I'm still happy to find new relations :-)
For now I will keep noautologin in auto/config as I can't see anything telling me how to put this option into my live-config conf file in binary_local-includes/live/config.d/my.conf