I started playing through all of the origins and I figured I might as well post my impressions here.
1. Factory Automation
The handling of automation with edicts and planetary features is functional, but feels rather clunky. It would've been much smoother if the origin instead modified districts to directly produce resources instead of providing jobs. But I suspect there was a limitation imposed on modders to not override any vanilla files and the UI currently doesn't support enough different types of districts, so the choice is understandable. I also have a nitpick about the origin description, which uses "less pops" when it should use "fewer pops".
As for the actual content of the origin, it's extremely powerful and borders on an economic hack. Your basic resources, CGs, and alloys all get produced by the automated factory, so you don't need any pops for them. This means that you can largely ignore habitability on any planet that isn't dedicated to research. It's highly effective to dedicate planets of your capital and guaranteed habitable planets as population centers churning out science while low hab planets are used to produce everything else. You can also turn a new colony into an economically important planet much faster. You're not limited by population growth, only by your ability to clear blockers and build factories. All that also makes it an ideal origin for xenophobic empires, especially Fanatic Purifiers.
What I like about this origin most is that it shakes up the order in which you pick your traditions. You'll want to pick Domination in place of Expansion because you don't need the population growth bonuses nearly as much, but you do benefit from cheaper blocker clearing from the Domination opener. You can then either switch to whatever you'd pick usually or you can finish it for the powerful finisher of +1 influence per month.
Overall I'd rate Automated Factory with a 3/5. It has some good ideas, but I find those would actually work better as a general gameplay mechanic than they do as an origin.
2. Absolute Zero
This is a highly narrative driven origin. The warning that this is a challenging origin is accurate too. Without spoiling too much of the story you will have to dedicate a good deal of engineering research and alloy production to a special project, which will leave you with a weakened fleet. You also do not get any nearby habitable worlds, which will put you behind compared to empires that do. However, if you survive you will gain access to several special technologies that will give you a serious edge and help you make a comeback.
What I particularly like is that the military technology you gain gives your ships a very strong flavor and gets you to make an uncommon design choice. Also props for giving gestalts more origin choices. In fact it probably works best of all for a terravore swarm.
The main criticism I have is for the writing. It feels rather amateurish and there are still several typos. It's still functional, but requires a good deal of polishing up.
Overall I'd rate Absolute Zero with 4/5. It's a cool narrative origin, it's available for hives, it gives you an extra challenge in the early game and some cool toys to play with later on, and the only downside is the aforementioned writing. If that gets fixed though I'd rate it above all of the vanilla origins.