"Dark to Light" that the Q posts use is masonic jargon. In fact, it's basically like their motto. What does that mean in context? Honestly, I think the Q group were probably a group of freemasons using their connections to attempt to rally support. It would explain the occasional inside information (and the eventual failure of the operation).
Clearly, any mason should have known what all the dark to light posts meant, so I would assume that was perhaps some type of recruitment statement? I do not know enough of their methods of encoding information to pick anything out (nor do I have the motivation to go through it with what I do know), but I would bet that some of the posts are encoded messages using some type of masonic principles.
Also, I would imagine this is where the "who you are talking to" bit comes in, as masons are the target of a lot of negative conspiracy theories, therefore most Q followed would be shocked to know it's masons.
Darkness into light has been in the Bible and warped by the secret societies like freemasons, who use the Sun symbol to represent Satan in a perverted way.
Satanists like to pervert all of God's words and make a mockery. Thats the core part of Lucifer wanting to become God, but is just a faker.
For them "light" or illumination represents the knowledge of how to enslave humanity while following their own little set of rules and convincing themselves they are not breaking any rules.
Q has been reclaiming a lot of symbols from the Cabal. Its part of defeating the secret societies by taking over their symbolism.
Dark to Light is literally that - we have all been living in darkness for all these millenia and every one of us here who studied the Q drops have started to find ourselves emerge from this darkness into light of the true knowledge.
Even the number 17 is the same. It stands for victory in the Bible, but the Cabal also used it to rub it into our faces as a way of showing their victory over us (For example JFK Assassination). Q team reclaimed it back for the victory of Good over Evil.
Thanks for your Sage words, and bringing this to the proper light.