Isaaq know they must take Las Anod before any ceasefire. Once a ceasefire takes place, Las Anod is likely gone for good. This is why they are willing to commit all of their resources to this fight.
The problem is that Dhulbahante border Puntland & Ethiopia making it impossible to effectively siege Las Anod. As long as the Dhulbahante hold the city when a ceasefire is announced, Las Anod is won.
This is why Isaaq who otherwise would feel self conscious about advocating for the shelling of a city are advocating for it now. They realize the clock is ticking and that this change in the status of Las Anod is probably a fatal blow to recognition.
I hope Puntland is making sure sufficient supplies are reaching Las Anod.