A productive afternoon in terms of beta versions for developers and is that Apple makes the versions available to you macOS 10.14.3, tvOS 12.1.2 and iOS 12.1.3 beta respectively. In these new beta versions released we do not find watchOS but it will surely arrive in the next few hours.
In any case, the important thing about them is that Apple fixes errors and corrects some bugs detected in previous versions. All these versions are "normal" except for the beta version of iOS 12.1.3 since it is a version that should have been released later and not the final version of official iOS 12.1.2 that was released for fix issues with Qualcomm and its patents.
Be that as it may, we already have the beta 2 of macOS and tvOS in addition to the "beta 2" of iOS in the hands of the developers so that they can detect problems or possible failures in them. At first it doesn't seem like we have too many changes in these new versions so we cannot say that these are large versions, but they correct errors and are therefore important for the proper functioning of our devices.
Typical performance improvements and bug fixes are added in macOS 1o.14.3. Do not expect much more in these beta versions because of having important news sthey will surely arrive next year, this 2018 no major changes are expected at the level of system functionality. Beta versions for registered users will not take long to arrive if they are not available right now. If there are important changes in these betas, we will comment on them in this article or write a new one for it.