P.M.D.G. has stated in its independent forum that their High-Fidelity Boeing 737 NG has entered the Beta Testing phase of development: https://forum.pmdg.com/forum/main-forum/general-discussion-news-and-announcements/161143-12feb22-developer-update-pmdg-737-for-msfs-enters-beta-testing
P.M.D.G. previously explained that Microsoft and/or Asobo have not provide adequate debugging tools for developers. Thus, the time, effort, resources to competently and reasonably debug new and existing software on the platform is clearly unreasonable and have been extended “20 – 23” times longer than the Lockheed Martin P3D platform.