You mentioned in the description that "The main one is the fact that we cannot read the player's available missions via Lua." but there may be a way.

#### `bool` player.hasQuest(`String` questId)

Returns `true` if the player has a quest, in any state, with the specified quest id and `false` otherwise.

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#### `bool` player.hasCompletedQuest(`String` questId)

Returns `true` if the player has a completed quest with the specified quest id and `false` otherwise.

Sadly they don't simply return a list of quests, but you could iterate a list you built. One problem remaining - from the object context - the player table is nil. But you could hook the player scripts to add a couple message handlers to the players, so the object can message the player. For example I have this to verify a certain player is the ship's true owner.


That could be annoying to do for every possible mission. Because you then have to keep checking for an answer for each one (that isn't answered). So rather than message the player for each one, the handler should accept a list of possible missions and return a table of boolean answers to this question.
so that your return looks like
So with that, you can verify what quests the player has available. And a similar handler to know if they've completed the quest. So you don't have to guess. That opens up another important door - I believe this mod(for example) might not be compatible as is.

http://steamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=874013371

Once you have a list of their missions(and could probably ask their author to message you if they add more), you could just add those to the list of missions to check for. I don't believe it would be a problem to check for non-existent missions. If I'm wrong about that(you get errors), you could use root.assetJson() to check for specific things a particular mod adds, and in that case add their missions into the list of missions to check the status of.

If there is something you need me to clarify, let me know.