Arrgg. Sorry to answer that late. The game doesn't want to, like I want it to behave.
As far as I understand your idea, it is not the same as mine. But there are common grounds.
You create a script that contains references to different kind of missions, with at least some common properties and a group of mission screens to refer to and manage those missions. If an OXP developer creates her/his own missions, she/he could (and definitely should!) use your "board" as GUI instead of writing her/his own, which would fight over dominance with other OXP GUIs. In your board they play nice with each other as they use the common framework provided by it.
I want to create something very similar, but still different. I want to create a script file, that can be loaded as a world script (As part of other OXPs or in it's own OXP. As I do not want to change it afterwards if not necessary, every OXP's version should do the same as they are identical and have the same name! Only one will be loaded!).
Its first function should be: It should contain an index that contains references to another world script and one of its functions per reference. This function should contain a mission screen call. In other words, by reading a reference of the index, you end up with the data needed, to call a function that creates a mission screen.
Its second function is: The index is arranged in a certain way, so the script can place(call) those mission screens in between other Gui Screens.
For example: Instead of:
regional starchart(F6) -> large starchart(F6F6) -> regional starchart(F6) -> ...
more screens are added:
regional starchart(F6) -> large starchart(F6F6) -> thargoid invasion starchart(F6F6F6) -> Witchdrive configuration menu(F6F6F6F6) -> regional starchart(F6) -> ...
You write an OXP and want to squeeze your own screen in between standard screens. If someone else has the same idea, your OXPs will fight over it. If my idea of this script comes to fruition, both OXPs can use it, their screens get there position in the index and are called, when it's there turn.
The script would also contain a method to add a function to the index.
Both ideas should create more order and compatibility between OXPs. Yours focuses on missions and a detailed overview and management of them, mine wants to provide a safe method to place screens in between standard screens and keep that as open and simple as possible.
I saw you placed your bulletin board in the station menu. How does a position F5F5F5 in-flight sound?
Sadly, I'm running against a wall. (This is the reason it took so long to answer and why there is no sugar left in my brain to write a decent posting.) I thought the worldScripts management part would be tricky, but it turned out very well. The simple guiScreenChanged method is what's killing me! Turned out it isn't simple.
Can you upload a preview version of your OXP? Maybe I find something that helps me or I might be able to make suggestions for the worldScripts part of yours.