Hi I would like to notice, that if u would like to add a player you are currently playing with, you cant do that from game level. Even when there is overview after game, there is also no option to do that.
You can make it only after you back to the main menu, and look for “recently played”. Even if, this list isnt alfphabetic or chronologic (from newest to oldest game played), so u have to scroll looking for player and remember player name.
I think adding small “add to friends” next to “block” or “report user” in player list (during the game) or overview after finished game would be helpful