current state of r2rml-kit & D2RQ/develop?

[seralf]

Hi
in my team, we are currenting evaluating reusing an existing codebase which was developed using D2RQ for DBMS mapping, updating the language to R2RML.
We'd like to use the new version of D2RQ, but I'm a bit confused about the current state of the various forks? is this project the current state of the art, do we have to skip the develop branch from D2RQ?

For example I've done some testing using the version d2rq-r2rml-preview-v4 and as far as I understand, the release seems to be a merge between this project and the traditional D2RQ code: I tried the server but it gives me an error which seems to be actually logged in this project, so I suppose the final distribution is a sort of merge between the two. Please correct me if I'm wrong.

thanks in advance for any suggestion and clarification