ggtern is a great package that builds onto ggplot2 by adding ternary plot functionality. Unfortunately, the package has not been updated in over 9 years and officially ceased to work with ggplot2 after the recent upgrade to version 3.5. See nicholasehamilton/ggtern#57.
Is ggplot2 interested in adopting ggtern in some way?
Or is someone in the community interested in forking it and make the (likely small) tweaks to get it compatible with ggplot2 3.5?