Comprehension of Peak-Level Supreme Soul Stage
Davis continued to read and learn as much as he could from the records while comprehending them or not could only be done later after he had stepped into the King Soul Stage. For others, it would be the opposite as only after they had comprehended would they be able to step into the next stage in Soul Forging Cultivation.
From this, Davis understood that as long as an 'anchor' exists, it is possible for people to exceed their current limit set by a lack of comprehension. It didn't even have to be Fallen Heaven to anchor their cultivation base's foundation but a unique resource that allows them to bypass such a limitation. It was just musing on his part, but he thought that unique resources only allow for one or two bypasses while Fallen Heaven basically allowed him to bypass everything in Soul Forging Cultivation.