could you add some HTML editors in the “Text” boxes? You know, TinyMCE, CKEditor, OpenWYSIWYG or something like that. Answering to the client now is very hard without the tools for text formatting. Especially if more often than sometimes you need to present some information to the client in a more visual and attractive way. I know that I can write a text in the Word app and then paste it to Zammad but more suitable would be the possibility to do that in the Zammad window direct.
Also, enough would be those from slack for example (extended to adding font color and background):