Members of the beta for Nova Launcher will be greeted to a few new adaptive icon shapes this week, with Flower, Pebble, and Vessel being added from Android 11. When customizing app icon appearance in Nova’s settings menu, these options will now be available, so that’s sweet.
Bug fixes and optimizations are also mentioned in the changelog.
Too get in on this, be sure to enroll yourself in the beta or just wait for it to rollout to the public version. That usually happens a few days after the beta rollout.