I'm confused. I don't know what this thread is about. I re-read the Op's post's and I'm still confused. Whats the problem? Wet or dry, laying vinyl is laying vinyl. I mostly apply dry, but even wet, whats the problem?
What really threw me for a loop is this.
"but am concerned about the vinyl not completely laying flat once the transfer tape is removed after it's dried out."
Dont remove the transfer before the graphic is down. If you having trouble removing the transfer tape, spray it with some Rapid tac and let in set for a few sec. before removing it.
Since your location is top secret, I cant help with any tips concerning applying in the hot, cold, dry or wet...