CB - How to remove the "Select a connection to send a message" button

In the context of CB I have the following 2 questions. As soon as I am going to create and send a new message to another user it is going to look like this:



Question 1:
What is this button used for? As soon as I click on this button there appears a list of users. But: I don't know the exact criteria for a user to appear in this list. As soon as I select such a user, the username will be transferred into the 'To' field of the message form. But I do not understand the use case of this button.

Question 2:
I prefer to write the recipient user name directly into the 'To' field. So is it possible to hide this button somehow? In the backend I tried to turn off the follwoing switch:



Indeed the button mentioned above disappeard but then also the whole favourite features of CB (add favourite / manage favourites / my favourites) have been switched off. Could you please help me fixing this issue?

Regards

What is this button used for? As soon as I click on this button there appears a list of users. But: I don't know the exact criteria for a user to appear in this list. As soon as I select such a user, the username will be transferred into the 'To' field of the message form. But I do not understand the use case of this button.

It's a dropdown of your connections to quickly send a private message to someone you are connected to. This will eventually be gone as ideally would prefer the input to just have auto complete, but it's a transition feature since everyone went from UddeIM to our internal PMS we wanted to keep some of the heavily used features. The next rebuild of the PMS will be more like chat.

I prefer to write the recipient user name directly into the 'To' field. So is it possible to hide this button somehow? In the backend I tried to turn off the follwoing switch:

Yes, edit the Private Message System plugin in CB > Plugin Management and adjust its parameters from there.