Add an option in the settings to toggle between anyone being able to start a base defence mission (as it is now) and only the host being able to start them.
I have been thinking about this for a long time, and I really see no negatives in adding such a feature.
It has happened so many times that a random player comes into my world and fast travels to one of my bases and immediately starting a base defence mission on hard. Meanwhile I am in a big fight somewhere else on the map and can’t make it to the base. When I well can either the base is destroyed or basically everything is smoking or is broken. Then I have to spend many resources rebuilding and repairing everything.
By having an option to only let the host start them this problem would be eliminated.