There are 2 minor annoyances when adding a player to your party: 1) Not being in the same channel. 2) They are already in a party. - Is it possible to add someone in a different channel? - Is it possible to automatically send the player you are trying to add a notification that you are trying to add them? To prevent unwanted spam, we can perhaps limit the rate of notifications. I can't really see a downside of these changes if they are feasible. The minor annoyances are so common and have been around for so long that I have taken it as a given, but it would be a great QOL improvement.
Posting as a player not staff: I think this would be an awesome QOL change if it is even possible. For me the first suggestion (different channels) would be especially awesome. I can’t even count how many times I run into the issue of having to switch to the channel that someone else is on.