safe salmon
If you don't enter the shuttle, the mission completes. There is no reason to board it other than to leave earlier. I suggest a mechanic where mission completion is triggered to players who boarded the shuttle. Failure to board, forces you to call in another one.
For griefing protection, a host migration could be implemented. In warframe, endless missions can be individually extracted without pulling the rest with you, and without others keeping you inside. This is my personal desire. Check with the majority to see if people feel the same way. It isn’t worth working on it if most people are fine with it.
opal gust