Not normally one for forums... Just want to reitterate what others have said. This isn't hard mechanically, the randomness is the issue. You can't have a boss on a time limit where it can spend an arbitrary amount of that time invulnerable - it just doesn't work from a design point of view, but especially given that the RNG seems so heavily skewed towards that stuff that makes it invuln. Remove the RNG, it's really that simple to fix. I'm all for more challenging content - I've raided, done CM fractals, solo'd dungeons and T4s and it's all fun because it's at least fair. This isn't fun because it's straight up not fair. I genuinely don't want to get egg from vendor - I want to get it from doing meta but I'm fed up of having time wasted over and over again by a badly thought out encounter.
Additionally, I can understand frustration with players in the squad that get continually downed by every mechanic. It's not hard to move out of the orange area - theres nothing even remotely elitist about that. It's the most basic of basic mechanics and still everytime I do this meta, I'm seeing 15-20 people getting downed by every single thing despite being told over and over.