I agree with @HAWK in that you need to choose your staff wisely. Regardless of volunteer or paid
Volunteers should generally typically restricted to tl4 or category mods
Imho there should also be a Top Mod Level without the need to be an admin to be able to manage other full site mods. That can silence/suspend other non top mods.
Because of the powers a full mod has. They can easily without care destroy a community with abuses of power.
A member in my community at one time created a tampermonkey script that added an option to block/mute users in the form of an external theme component browser extension.
The idea though if extending the block option not hide posts decorated by staff colour is a cool idea. Members need to know if they are having issues with one of the mods they can contact another mod to intervene if needed.
A problem with muting a mod. If that mod realizes they are blocked they could choose to use mod powers to cause the user a lot of greif.
Here is a link to his topic. It was at that time I believe Discourse did not have a block feature. Also provides some other nice goodies.
It would need to be updated to reflect changes in discourse since it was made. And could likely be made into a TC or kept as a browser mod extension