Does Groff have an updated formatting algorithm (Knuth-Plass/other)?

In the groff mission statement it says that Groff will be moving to an improved formatting algorithm. Considering that the mission statement was written in 2014; I was wondering where this was at development wise. There is nothing I've seen in the git logs that might indicate this has been worked on/completed, but there is a mailing list archive that shows some development. Thank you very much in advance for any help