Most wood at the campground is too wet or dried/packaged the same as gas stations as you've observed. If a private campground says no outside wood they will likely check as they are counting on that extra revenue from the concessions. A state campground will go by the rules established by that state. In my experience most don't check. One I go to doesn't check hard but are a bit more nosy than the rest so I set out the decoy bundles and bring out only a few pieces of mine at a time as a precaution. As you are pulling in take a look at the other campsites and if the wood is laying out freely you likely won't have a problem. If everyone has the orange fishnet bundles by the pit follow suit.