Based on prior postings it appears that the judge might not be able to directly compel the DC legislature to pass shall issue but I see no reason he could not put the injunction back in place until such time as he was satisfied that the new law complied with his Palmer-based ruling. So they can pass may issue, but then DC becomes constitutional carry again.
And then DC appeals to the circuit, who then grants another stay until the case is heard.
And so it goes..