We’re in the final testing/bugfix round for v5.0. It got largely delayed as we decided to incorporate some very extensive new features where testing took much longer than expected. We want to start a public beta round, soon. Whenever there seem to be no more issues, we will release officially.
For v6.0, nothing is known. The code - as such - works, can be developed and tested for, however, only a part of the features has been implemented. As we do not have many React developers onboard, it is completely unclear when we manage to get all the features added. It may take only a few months. It could equally well take one year or somewhat longer. At this point, it largely depends on external contributions. And there aren’t all that many.