I don’t think using a fallback would be something good if you don’t see it is actually using a fallback - although we could play by using an icon so you can see that it’s using a fallback - in that case it could be acceptable - and of course an extra setting should one not want this.
A copy button (2 ways) could be done, I’ll write that up as an idea.
Marking the field red is also possible, writing that one up too. Thank you.