A few things I wanted to add:
The general issue was definitely just the ongoing topic of speed & freshness when decorating fancy cookies. I think I should have (as above, with @Kelly's response) used my sealer more often and broken production into into stages more. But I had bitten off a big bite (metaphorically) and was trying to just blizzard my way through things...
I would *not* use apple for this in the future, it imparts too much flavor, and a slightly off one at that, just because it's a perishable piece of food. I felt like the flavor spread -- from just one cookie -- to other cookies a bit once I had them all back in a big box.
Similarly, I would probably not prefer to do this with bread again. Or if I absolutely had to, only with plain white bread. There was less flavor/smell from the bread than the apple, but I still couldn't shake the slightly bready smell - to my nose at least.
I decided that in the future if I needed to do something like this I would use a brown sugar bear or the homemade equivalent: a piece of pottery that is soaked with water and slowly releases moisture that is absorbed into the cookies.
It was a decent stop-gap measure -- I think -- but I ended up being in agonies, kinda, about the quality of the cookies, when that's not something I am normally that worried about. They didn't *seem* to have that beautiful buttery/sugar smell right off the bat anymore and I was still terribly worried about them being too hard. But perhaps I was paranoid 
. I don't know. Anyhow, I definitely think the answer in the future will be to be more aggressive about breaking things down into stages. Also to try a brown sugar bear! (like this)
Hope that's of some help. Again, I appreciated the responses & chance to talk it out --