I have found one of the best ways to make it passed waves 36-49 is having a tether hunter and a someone who can maul down adds. One build I’ve been using to add clear is Tommy’s matchbook + actium war rig on solar Titan. With the catalyst, Tommy’s scorches on impact when fully ramped up, and if done correctly, can ignite entire waves of adds. The right solar fragments can help ignitions scorch other targets which results in a satisfying chain of explosions. However this build makes you a bit of a glass cannon as Tommy’s puts you in red health while it’s firing, so if you do try this build, always make sure there’s a quick escape for cover. The best way I’ve found to use it is to look for the beefiest enemy and start firing, creating ignitions that will take out the red bar enemies next to them. Pairing this with a tether, especially in later rounds when even red bar enemies are beefy, is a great option. Arc warlock with crown of tempest is also really good and can do similar add clear with the fragment that jolts targets hit by grenades.