Rather than spend 30 minutes struggling to make it through, I'd just keep fast travelling to the same location in the hope you get an instance where they're already at the 5th or 6th round. When I was looking to get the weapons it worked well without having to spend too long finding good ones. I always go for the top area, too, as the bottom one seems a bit arsey and awkward sometimes due to terrain and the sprawling environment.
It's working now. happened into a couple instances that beat level 7. Now just one EP armor piece away for that badge. I need to do the NF to get another key first though (I had 2), and I'm waiting til Thurs pinnacle fix.
Do the old 820 NF's still reward 7 key fragments?
After that is completed just need one Mars Heroic adventure, one Mercury heroic adventure (time gated until they are the flashpoint, which at this rate will be never), and the emblem you get for doing all ascendent challenges of which I have 5/6 (I've done all 6 but it just didnt count one, and I was too lazy to do it again that week, so now I gotta wait for it again). Alternatively supposedly that emblem is a rare drop from Blind Well, but I haven't been able to steel myself enough to grind that yet, too boring. Oh and still need to beat a couple lost sectors on EDZ I think, that's so easy I dont even count it as not done.