I've just learned out, that openSUSE zypp has wery useful configuration file /etc/zypp/zypp.conf, which contains crucial option solver.onlyRequires. If you set it to True, only really needed dependencies will be installed (of course you can install other packages manually).
This should be also possible to set during the installation. Just need to set the value from console before the libzypp is initialize - during first few screens of installation. But don't forget that it must be set after reboot/kexec as well so it is also valid for 2nd stage of installation and installed system.