I had a similar experience with running out of usage quite quickly, after setting up one design system properly, and then getting pretty close with a second one. But it's a research preview - I'm sure it will change.

I was quite happy with what I pulled off using the first design system: I wanted a new footer section for my IPAAS startup, it generated four options, the fourth of which was quite good. We iterated on it for a bit, then I pulled it into Claude Code (that integrated feature is very cool), CC built it, I deployed it, done. (Bottom section of https://tediware.com/ if you're interested, the bit with "Origin story" on the left and the signup panel on the right).

It was not a complicated build by any means but I liked the concept it developed and it was dead-easy to make it all happen. I think the ideas in the UI are very good. Still rough, but you can see where this could go, and it's got a ton of potential.