Also I'd really strongly suggest that you push your company away from a team @ alias and toward a team channel. The only groups that should have an @ alias that punches through notification settings are on-call, and if your role IS on-call then no amount of Slack changes will reduce interrupts.
People create one @ alias per team and also many others for subteams or temporary project teams, etc. There is one for oncall too. Every time one of those aliases gets tagged, I get a notification, an orange counter or sometimes messages from Slackbot asks me to join the channels.
*> punches through notification settings
I'd like to specify which aliases should not be ignored but I can't in Slack, unless I'm missing something.
Also, disabling the oragen counter is not possible (even for muted channels).
