Can we have mariadb-libs like postgres ones? Mariadb is fat, mostly unneeded, package.

Please don't pollute existing threads with unrelated requests, split off for you this time.
Splitting is pretty much being removed from KaOS, see the website regarding reasons, only splits left are those to keep the main and core build chroots clean. Mariadb is not part of a base chroot install, thus not needed to be a split package any longer (yes, it used to be split).