It's very much a work in progress. There has been a LOT of behind the scenes work on the frontend repo to do everything from upgrading the version of Bootstrap to making it easier for theme, userscript, and extension developers to make personalization options.
There's also work happening around improving the visual style of comments and posts. Prior to the reddit exodus this was being developed almost exclusively by two people, now there are a LOT of cooks in the kitchen and we're all finding where we can fit in and start making contributions.
If you use any of the userscript extensions (Greasemonkey, Tampermonkey, etc) this is a pretty useful script that improves the layout. It will however botch up all of the nice theming Nina has done on crystals.rest.
Here's a screenshot of how it looks:
However once v0.18 lands the work that I and others have done will make it a lot easier for people like Nina to dramatically overhaul the UI and make it more aesthetically pleasing, and those core improvements will keep trickling in with future releases.