This is an outstanding guide on lost sectors. It gives great tips on loadouts, etc. https://twitter.com/legionlesstv/status/1434199587967827976?s=21

Graviton Lance is actually pretty good with unstoppable mod, and is great against swarming adds. Take your time and [i]don’t close with the bad guys.[/i] Kill everything from cover at as much range as possible. Remember—you get an extra res for each champion you kill. I did Chamber of Starlight yesterday using Solar class with thermoclastic strike for the overload, kinetic sniper, Graviton Lance (void), and Avalanche (solar mg). Using cover and killing from a distance made it (not quite) trivial.