So do the Melnorme stay in the sector indefinitely, or do you  have to purchase everything before they leave?

Hello,

     I have downloaded the UQM HD beta. It is absolutely beautiful. My main beef with the game is that the Kohr-ah take over the galaxy in like four years. I have read about mods that give you another 100 years or so, thus giving you plenty of time to explore. Is there a mod compatible with UQM HD that can do this? If so, then where can I find it?

thanks