Already added.

Planned for v5.1

WhatsApp will be getting revamped very soon, so I am hoping that this will fix it.

Either late this year or early next year.

I will investigate and test. If the chat looks okay with 24 users then I'll change this

This would be a great idea, I'd like to at some point.

I will take a look into this

Now that you'd be able to bring iPad apps to macOS Catalina, I still do plan to bring to Mac at some point. For this case, it will become available on iPad next then macOS or even both at the same time.

You already can. Visit Lock Screen and the Phone account to do both of these.