I am hosting a 7 days to die server, and I'd like to open it up for crossplay. 

How do I do this? 

This was answerred on the Discord. The developement team for ARKServers.io is working on getting the new setting updated on the panel, but there have been some personal life delays. Typically it can take up to three days for adding the setting, testing the setting, and then rolling it out to the public, but it may take just a bit longer this go around.