Hi Artem,
JJB is effectively in maintenance mode at this point. Unless there are people (or organizations) willing to put in the effort to take over the project and lead development it is unlikely there will ever be new features to JJB core code. As one of the remaining core reviewers, I no longer have any use for JJB in my day to day so am only maintaining and reviewing patches from the community to keep the project alive. I stated this concern awhile back in this mailing list thread [1] in case you're interested.
Most of the patches coming into JJB are fairly simply additions of new Jenkins plugin features. Very rarely do we get JJB core changes these days. Unless you or your organization is willing to put in the cycles to implement such a feature and contribute it back to the community, it is unlikely that any new feature requests will get implemented. Until then I plan to continue to review community patches and occasionally produce new releases.
Hope this helps,
Thanh