I'd love that but I'm afraid there might be some technical hurdles to achieve it.
Granted we're talking about the sort of problem that *can* be solved, but as usual it would require work, perhaps much work, likely more than they're willing/capable to pull off.
Each Slip item has a field with a string of hex characters that are used to tell which items are inside the slip.
Imagine like a binary grid where each box represent an item and can hold values 0 (no item) or 1 (item stored).
That is basically why we can know what's inside the slip with the addon "Find" even without trading the slip to the moogle, it's because that data is stored in there.
My binary one was just a silly simplified example, technically they're using HEX characters.
I think each character represents 4 items slots.
Someone more competent than me will be able to explain further details, but in general it's close to what I described.
Of course you wouldn't be able to do this with KIs.
Would that bother me? Honestly, not that much, but I'm not SE hey.