Yeah, that’s the only weapon I’ve been successful with on Master.
As far as the new cabin goes, the rate of charge is the big question.
If it’s a fast charge when you’re next to a wreckage, it will work quite well with close range builds, as you should be touching a wreckage after killing your victim. Assuming you don’t have to hang out too long to charge it, you could trigger the perk right after disengaging from your victim.
If it’s a slow charge, it will play out differently, but should still be useful for close range builds.
I’m definitely not suggesting “hanging out” around wreckages (although there’s nothing wrong with using them for cover). My assumption is that just driving by them should gradually charge the perk.
I don’t know about you, but when I play close range I’m constantly in motion and travelling all over the map. It’s normal to be encountering wreckages when doing that, and many of them are far from the action by that point.