Bait PILE? If you really mean pile... don't pile it. Take a little bit of time and scatter the corn. Deer don't need to see a 10" deep gleaming pile of corn in order to be able to find it. Also... the only reason to put corn out before season is to get pictures. Otherwise you are hurting yourself instead of helping. I'm not saying don't do it but just know what you are doing it for. It is not going to help you kill a given mature buck during season and it will probably be detrimental.
Once season is in look to scatter it in a cut corn field if at all possible and if you can try to start it immediately after the corn is cut. If that isn't possible another food source like standing beans, clover, etc would be an ok choice. Two problems I see with corn in the woods... it's not natural and it too often has young deer laying too close making approach impossible. You can't blow fawns and spikes out every time you show up and expect to kill a big deer there. If in the woods is your only choice then you need to pick a spot you can access with least risk of bumping deer or being seen.
You are saying you want to kill big bucks on your corn. To do this you have to break it down into 2 different scenarios. 1) He's coming to eat corn (which means early season thru mid Oct and then again late season) or 2) Prerut/rut where he's primarily coming to look for does that are eating the corn.
For scenario 1 you have to think about the fact that he is in wary survival mode. Because of this he is not going to want to consistently frequent a spot that is inundated with deer activity. This is why he comes inconsistently and eventually almost exclusively at night. Think about what happens to a spot where you have been feeding corn for 2 weeks, a month... it turns into a hoglot. Sure he still shows up some but as you said there is no pattern and it's almost all in the dark. You will never kill him like this. The key is to only put the corn out right before you plan to hunt. Next (and this is the key) you have to know when he finds it and hunt him immediately. If you put corn out and set a camera and go back on day 7 and run the camera and see that a target buck found it on day 2 or 3 and has been there during daylight... you get excited. Sorry it's probably already too late at that spot. You missed your window. When they find it you have to hunt in the next day or so or your chances drop off the cliff. The day after they find it is your best chance. I've watched this unfold on big deer a hundred times by now. They find it and then show up during daylight for a couple days and then they quickly fade back into inconsistent nocturnal oblivion. If they have already done this by the time you see they have been there... it's over. You have to know the instant they find it. Cell cameras are the best and probably only way to pull this off unless you can watch the spot every afternoon from a distance. If you don't have a cell camera then you have to go in blind. I'd go on days 3-5 after first putting it out as that seems to be the sweet spot. You can't run a regular camera every day or you will screw yourself with scent. If you can't make it work in that spot... let that corn go to zero and wait a couple days and try again somewhere else. This will be way better than just pounding the same spot into powder with a long running corn pile.
For the prerut/rut scenario it's much simpler... probably not as successful but simpler. Don't try to get him to walk up into the corn so you can shoot him. Run 2 spots at least 100 yds apart and you hunt between on the travel route he will use to check them. Choose your spots so that he can travel in reasonable security cover to visually check the areas where your corn is. For this scenario it is fine (even preferable) to start this corn in early Oct and keep it going. You don't care that he is too wary to walk in during daylight to eat because that's not what you are trying to get him to do. Even if he does by some miracle... that is not his main purpose and you are still sitting there waiting between the spots.
Anyway these are my opinions and thoughts based upon experience and are built heavily on me chasing my tail for years and always being one step behind big deer. You have to be ready for your windows because they aren't open for long. If they were we'd all be killing a lot more big bucks.
Good luck.