Would love if CU Chat had a way to see who has seen a message already and who hasn't.
For businesses like ours that are distributed and complete work at different hours, read receipts are massively helpful in knowing when/when not to follow up (and not having them was probably the most frustrating thing about using slack)
I'd be okay if this were a ClickApp and were toggleable at the company level. A model to look at could be WhatsApp.