We at AEM HQ are big fans of the ACS AEM Commons project. While many have contributed to the project over the years, a lot of credit is due to @justinedelson and @unicornless for their commitment to the project. In the coming months, you can expect Peter and I to continue our series of deep-dives into the project and the features it offers to operations, developers, and content authors.
Now that AEM 6.4 has been released, I reached out to Justin to ask him whether there were plans for a 4.x branch of the Commons project which would drop support for AEM 6.2. He pointed me to this GitHub issue, where he is soliciting feedback from the community on whether the time is right for such an effort. Maintaining 6.2 compatibility requires the project to continue to carry support for deprecated APIs such as com.adobe.granite.confmgr.Conf - which has been replaced with Sling Context-Aware Configs - or AuthorizableUtil.getName which has been deprecated in favor of the multiple profile aware AuthorizableUtil.getFormattedName.
If you are using ACS AEM Commons, and you have an opinion on the matter, we at AEM HQ encourage you to go weigh in on this issue.