“As a result of that principle of undifferentiated encoding, any perception of and any information about the world must be a product of the mind.”

Is also a non-sequitur. Information about the nature of the cause of a stimulus does not need to be encoded into the stimulus itself. It is already “encoded” in th4e fact hat it comes in on *that* particular nerve. This is easily seen in phantom limb pain, where the suffer feels pain in an amputated limb, because nerve signals are coming in to the brain
from the nerve that used to lead to the limb.

This is of course not adequate to sufficient to reconstruct a complete picture of reality.
but it is not so insufficient that we can say reality is a “construct of the mind” in any
black-and-white sense. What we take reality to be is a piece of educated guesswork that is neither doomed to fail nor guranteed to succeed, and
we can still employ the Correspondence Theory to measure its degree of success.