You know, the Gates work so well in Gay, Lee, and even Kakashi because they are very physically resilient. If Hisana that is a total glass cannon uses the gates, she would be hurt badly, and even if she can heal herself, once the gates have been closed Hisana would be left in the open, extremely vulnerable to anyone.
If we don´t manage to increase Hisana physical resilience by a wide margin, the gates would be a Death or Glory technique and those are at best an Ace in the Hole, we cannot base our regular fighting style in techniques so dangerous for its user.