These plugins would allow users to take much more direct control of their post formatting, allowing regular users to take control of crafting how their posts appear, especially with colored text to help differentiate things, and they will also allow new users who are familiar with BBCode but not markup to more easily acclimate to Chief Delphi.
In short, I think it’s a good idea, and they have been very helpful on two other Discourse instances I use often that have them installed.