Has anyone looked at using ALIGN https://github.com/ALIGN-analoglayout/ALIGN-public with the sky130 process?

Yes, I worked on it, you can see my repository https://github.com/thesourcerer8/ALIGN-public

That's great! Did you get to a point where it could be used in practice? What was the most challenging part?

Interesting.

The ALIGN paper mentions that with more modern process nodes the design rules are stricter and allow fewer design options, which makes it easier to automate layout. I don't know if this means that ALIGN will work well only on more modern process nodes than 130nm

Well, another question is whether those rules are easier to implement in ALIGN 🙂