I can copy usernames and passwords into the clipboard, and I can type the clipboard into the tab. I frequently use these in combination in certain instances where paste doesn't work. It would be nice if there was a "Type Username Into Tab" action and a "Type Password Into Tab" action. Maybe just like "hold shift while selecting copy" to get it to type into the current tab instead of having a whole new UI.
you can pretty easily create key sequence tasks that do just that.
Just create a new key sequence task, set it as favorite and enter $EffectiveUsername$ as it's key sequence, then execute this task against the running connection (Tab - Favorite Key Sequences - Key Sequence Task Name).
As for the password, just use $EffectivePassword$ instead.
Hope that helps!
In this case you can copy the username or password to the clipboard and then go to "Tab - Favorite Key Sequences - Type Clipboard". Alternatively, if this is about RDP connections, you can also go to "Edit - Paste" which will essentially do the same as "Type Clipboard".