If during that time, one has a sufficient supply of elixirs, a relatively safe environment, and someone to protect them, they can attempt to break through to Foundation Establishment on the spot.
Like Meng Guan and Wei Fan, when the two were trying to break through to Foundation Establishment, they both went into a quiet chamber and looked for the opportunity within.
As for He Song.
With the Smoke Array hiding him, He Song didn't need to look for opportunities in a cramped chamber like Meng Guan and Wei Fan.
On the contrary.
He Song could walk freely within the coverage of the Smoke Array.
Even if he walked several miles away, he could attempt a breakthrough to Foundation Establishment anywhere and anytime.
It's not that He Song didn't value his safety.
It's because he could control the Smoke Array to hide himself at any time.
