released an updated ACE3 version on the BI forums
The changelog is very long and can be found on our downloadpage.
They have also updated their compatibility addons to match the newest ACE version.
This mod is entirely open-source (we are hosted on GitHub), and everyone is free to propose changes or maintain their own, customized version as long as they make their changes open to the public in accordance with the GNU General Public License.
ACE3 is built modularly, thus a team can maintain its own tailored version, excluding a select number of components that they don't like, or which conflict with other addons. Larger components themselves, like the medical system and other core features also include various customization options, allowing mission designers and communities to tweak the overall experience.