Put it up and get in it, I see no reason to wait. I don't remember ever having a deer spook at an inanimate object.
I put out a T-post mid-season just as a way to judge the height of the deer around it. That was several years back. I remember watching a doe come into the clearing, see the T-Post for the first time, then jump back as if startled. She came back, but was very skittish and never really settled down until coming back several more times.
Now they come in as if it's been there forever, not paying a bit of attention. Saw the post and just had to relay my memories. Just one man's memories . . .