I've run the super AG several times before, but without Fleshcrafter and they were basically immortal. You'd have to have some massive, MASSIVE degen to kill them. My AG used to wander into Sirus storms and just sit there and you'd watch it go from 100% to 98% hp back and forth. I always used a recover 15% of life every 4 seconds over 1 second Hunter chest with crafted maximum life as ES on it with the Stitched Demon and it was an absolute monster. Fleshcrafter, however, does make it a bit less tanky as it loses a lot of life for extra ES which it can't even regen. My AG without Fleshcrafter was something absurd like 90khp and 40k ES or some shit which made it a God. The Fleshcrafter versions obviously are going to reduce this to almost half which is rough because I've had plenty of 45khp minions get fucking obliterated by bad mob combos in previous leagues and it's probably worse now.
Just checking around seems like a lot of people use Oskarm gloves on their AG for - chaos resist to bring them closer to 0 total Chaos res. That + windscream boots allow you also to put an extra Ass Mark on the mob if your AG hits it. Looks like some people even use a Geoffri's chest for Zealots oath to apply life regen to ES too which doesn't seem to bad except for chaos damage hitting through your AG's ES.
I can confirm AG's definitely don't dodge pinnacle boss moves, they just straight tank them for the most part. A lot of AG's are run on Meat Shield too so it's on you to make sure you're dodging the best you can as well.
Unrelated to anything AG, I did Uber Cortex twice yesterday. Fucking thing has an inherent "monsters take 70% reduced damage" modifier on it. Fucking nuts. My first one also had 80% to all monster resistances. I was pretty spooked going into the fights since you fight two bosses at once each time, but their HP doesn't seem to be scaled up at all beyond the lvl 85 modifiers inherently. They pretty much got burst down and I just leap slammed around the arena clenching my ass why my totems went to town. Died once because I literally though the bosses were dead and one of the Synthete dudes flew down from the fucking heavens and blasted me. Second run was deathless and had 0 defensive modifiers for the mobs so they melted even easier. They did have 700% increased crit chance and 30% crit multiplier though which could have been nasty. Loot was shit, all 6 of the tri-implicit items were awful. Two Nebulis with low tier implicits. Luckily I found both maps so it was all a net gain.
Probably going to try Uber Exarch again, but looking at the "rewards" for it it's more of an ego thing than anything. Wish it had increased drop rates of the good shit, but that node is right below the Uber node so why even bother. I'd rather blast an 80 quant normal one I can insta kill than dance around like an asshole for 6 minutes and lose 30% of my level for essentially the same rewards.