Not Weak

The action of going for the Chasm wasn't completely madness. Back when Aelrie told Rean and Kentucky about the weakening of the Chasm, she said this weakening was coming from the bottom. The further up of the Chasm their perception was, the stronger the Chasm's power reflected in their minds. 

As they approached the city, they became even capable of talking without having to find specific closer points in the borders to make their voices reach the other side. That meant the Chasm's Spatial Power was already lower at the exit, and the bottom was even more so.

Nonetheless, the power exiting the Chasm was still fearsome. Rean and Kentucky didn't know if something could happen if they tried to traverse it either. If not for this meteor shower, neither Rean nor Kentucky would risk charging into it.