Nick's Zephyx Synchronizer was attuning to the Maw.
Sadly, creating a hole in the Specter Core could prove disastrous for Nick.
Cracking the Specter Core with pressure created a fracture that went along one of the manipulation lines, which made it easily repairable.
However, breaking through the Specter Core via forceful implementation of a blade created a deep cut that didn't go along any manipulation lines.
This meant that fixing the manipulation lines after repairing the Specter Core wouldn't be as easy.
The problem was that trying to break the Specter Core in the same way the Maw had broken it was far too risky.
To be frank, the fact that Nick's Zephyx Synchronizer didn't break under the Maw's forceful grip was sheer luck.
It could have easily broken in two, which would have represented Nick's death.