We really need support for groups and groups limits. Currently, we allows our users to create unlimited amount of MariaDB accounts while we have max_user_connections=10 so one account can't overload the whole database server. This can be easily bypassed by creating several accounts and use number_of_accounts*10 connections. It will be possible to prevent this using groups and group limits, for example:
max_user_connections=10
max_group_connections=30