Hey,
I noticed that every file in the 10.11.4 Beta /System/Library/Extensions is dated back to Mid-September and in the final version of 10.11.3 most are dated Mid-December.
That may explain the not working USB port for 3.0 devices with the new iMacs coming up in every Beta again, when all drivers have a date before they were released.
And also maybe some other problems.
I noticed that every file in the 10.11.4 Beta /System/Library/Extensions is dated back to Mid-September and in the final version of 10.11.3 most are dated Mid-December.
That may explain the not working USB port for 3.0 devices with the new iMacs coming up in every Beta again, when all drivers have a date before they were released.
And also maybe some other problems.