In order to use the trial version of Data Abstract you need the latest version Delphi installed. The commercial version does include support for all other versions too since it’s compiled from source if I remember correctly.
The simple reason is that due to the fragmentation of Delphi versions installed the installers simply grow too big. That’s my guess. Remember the days when Delphi versions were shipped twice a year. From the perspective of Remobjects technology all these version did offer simply the same. Pretty much the same counted for most of the Delphi developers.
So far I can just tell you that setting up a latest Delphi in a separate box and installing RAD Studio together with Data Abstract does make sense. If you are going to evaluate Data Abstract doing so is worth the effort or simply ask Salem Saberhagen aka. Evgeny the black cat.