It's been a week and nobody's figured it out. Just post the solution so we can roll our eyes in annoyance at the probably ridiculous, arbitrary thing that you thought anyone would guess.
Spoiler: hint level 1
Spoiler: hint level 2
Your hints are worthless. You're telling us things we already posted. Like I said in my previous post, the grid was the obvious thing that was apparent in the first few minutes.
The number of things that could possibly be done with it is effectively limitless, and without any way to narrow the field one could easily spend hundreds of hours trying things that could legitimately be the solution, but we have no way to know. For example,
rot13 is a standard cipher. I tried it. You're not using it. But hypthetically, if you wanted to be difficult you could have used rot- any number from 1 to 26. That would be a competely legitimate thing to do. So, what...shall we try every single rotation from 1 through 26? No, have to do it 26 * 4 times because the message could be read left to right, top to bottom, bottom to top or right to left. We could probably guess that's it's not top to bottom or bottom to top because you have that "AAdAAaaa" line in there, and it's probably unlikely that any encrypted message would contain five of the same letter in a row. So that reduces it to only 52 thingsto try...just for that one method.
Or we could go through various other lists of
standard substitution ciphers, and simply try them all. Or maybe you recently saw Futurama, or played Starfox or saw some movie or game and decided it would be fun to use a cipher from some arbitrary
pop culture reference. Or hey, maybe you made one up of your own in which case there are only 26 * 25 * 24 ... = 403,291,461,126,605,635,584,000,000 possibilties. Oh, and multiply that by four because again it can be read top to bottom, left to right, etc. Either way, if that's the case, then the encoded message is literally
any possible 112 character string and there's absolutely no possible way to vet it because literally any possible text of that length might be the answer.
On the other hand, it's noteworthy that there seems to be no punctuation, so maybe it's not any of those at all. For example, I already suggested it might be a paintbrush image.
Your puzzle is not interesting enough to spend literally multiple lifetimes trying all the things it could possibly be.