If we stick with using dynamic layer support, I'd be very strongly against putting them into meta-agl-bsp, that would be difficult to make work for users who do not care about meta-agl-ic-container. If for some reason you do not want the overrides in the main recipe, then having them in a bbappend that sits beside it is perhaps okay.
Major
https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-devel/+/28785/8