Proposal
Suggestion to add a party finder list to the missions tab populated with ongoing public parties. Situated somewhere either within another menu or in an empty space of the mission menu screen.
Reasoning
Currently, unless using the Arcade, the way to find public parties for missions or specific stages is to search for that specific mission and use "Join Party". Adding a party finder list that presents all ongoing missions that were made public can allows players to join groups swiftly and with ease. The list can also help incentivize more public parties as there won't be as large of a need to use zone chats or ask in haven for players to join for certain missions as well as the need to use commands or other players to invite members who are not on your friends list.
Suggested Limits
The party finder list should not allow players to join missions that are beyond the first stage (or depending on how it's made, beyond the ready room). This will keep players from running boss missions and inviting alts or other players for easy tokens. Essentially keeping the join party function as it already works now.
Misc. Suggestions:
Adding tabs for Friends, Guilds, and All should players have too many active players on their friends list at one time.
The party finder already presents Rank and Prestige Missions, if you can join them.
It will not list those you can't join because of your rank and it will also not show parties led by players you ignore.
I'm not sure if it lists parties that left the Lobby of Rank and Prestige Missions. Probably not. I never saw those.
Is what you mean that it should extend the listing for Rank and Prestige from the Lobby to the first map or even further?
That would be nice, but some only have one map (event ones). So maybe those need an exclude flag.