Combining people's need for a global chat feature and the laziness for not using the Player/Party Search features:

Global LFG channel does not allow player input, and appears only when you place yourself into the Player Search, as "Seeking Party" status,
game filters out the party from the Party Search which suits the "Preferred Class" you placed in Player Search and display them on the channel, with a timestamp showing how long the recruit is going to last for.

This way, people crafting or gathering anywhere in the game world can simply click on their chat log tab and be able to know which party is available to them, if they contribute a tiny effort for the recruiters to increase the amount of Player flagging themselves as LFG. And there won't be a channel that players can flood with, making it hard to serve its purpose.

(Just a suggestion which hope SE dudes can take into consideration)