User blog comment:B214/Question and Answers 2/@comment-99.227.35.241-20140123192432/@comment-1359322-20140125191726

It's not like Issei won't explore the potential of his new body but currently he still can't. Since his current body is like a black box, nothing is known about it, that's why they are still having Rias, Akeno and Koneko take the precaution of draining his Dragon powers.

Plus, okay enough with the lame explanations, time for a bit of theories. I believe that since it's said that the small Dragon thing that appears from the Boosted Gear which Azazel speculates to be from Ddraig's awakening. I take that this is a sign that Issei's Boosted Gear is about to take the next step of evolution which would also lead to Issei's new power from his new body indirectly. And i also believe that next step of evolution for both Issei, Ddraig and the Boosted Gear can only be done through battling and getting along with other Dragons, thus the Fake Sekiryuutei.