Hello @PaulEllison ...
Totally agree with everything that @TrishaMeyer1 has stated. I'll just add that there's an existing Idea here in the Community that has lots of feedback and support for adding the RCE (Rich Content Editor) to the Canvas Inbox:
[Inbox] Add rich-content editor to Conversations - Instructure Community (canvaslms.com)
This particular Idea is part of a larger Theme called:
Improve the inbox functionality to provide for mor... - Instructure Community (canvaslms.com)
I'd encourage you to follow both of these so that when/if this opens for voting, you'll be able to participate in that process and have those conversations.
Hope this helps in some way!