New orb mother is out, and it is a blast!
First time though I soloed it in 54m, second time was with a group and we did it in 22m. Solo is... Time consuming. It isn't hard, it just takes a while.
First time I took Inaros, Rubico Prime, and a Catchmoon. The plan was to poke around a bit and take a look at deck 12. The boss fight was not really planned, but I had prepared a bit just in case I got stuck in it anyway.
Second time I took a Tomb Finger instead of the Catchmoon, since that was better for the longer ranges.
Build matters little as long as you are a bit tanky and can kill coolant spooders.
The fight goes like this:
1) Head to Deck 12, and go to the balcony in the far left corner of the main room, use the machine.
2) Shoot the rocks under the spooder's feet, then shoot the weak point in her side.
3) Grab canisters and throw them at the remaining weak points, then shoot them once you get the ice off. Focus on one at a time.
4) Run outside.
5) Shoot the little spooders before they cool off mommy. When she opens fractures you can put the canisters the coolant spooders drop into the fractures to get thermia canisters that you throw at mommy to make her heat faster.
6) When she overheats, jump onto her to get a cutscene of you ripping a bit off her. Shoot where the bit was.
7) Goto 5 until dead.
In the last phase she cools herself off periodically (you need to throw thermia to overheat her), but each cycle she heats faster/more so even if you suck you will get it sooner or later. When she dies, there is
big boom so grab your loot and run.
EDIT: You only need one Dilute Thermia to start the fight. That is, one for the whole squad. This means that if you run 4 fractures with a squad of 4, you get the stuff needed to fight the boss 8 times (since there is a booster in effect right now, without the booster it is 4 times).
EDIT 2:
A short video with the highlights of the fight.EDIT 3:
Stream excerpt of the whole fight with a lot more detail and better strats.