Just looked at the source code: distrobuilder/gentoo.go at master · lxc/distrobuilder · GitHub
@stgraber @monstermunchkin Do I read correctly that the regular stage3 image is hardcoded?
So it only varies according to architecture.
@kjh1004 would like to use a different image: current-stage3-amd64-hardened-nomultilib-openrc/