Assuming I were to take the pack, hop on a train or something, and lose them and somehow either transport it safely or remove any potential tracking device in the train bathroom by cutting open carefully and retaping so it doesnt look opened. Would they just keep chasing waiting for the right time?
And when I say drop is not tied to address I also mean nothing is tied to that address. Utilties, bank statements, bills, anything.
Usually they would watch you from down the street or in the parking lot or in the office and wait for you to pick it up. Then they would arrest you after confirming that you took possession of the drug pack. That is a controlled delivery. They might let you go down the street a little and then stop you.
There is another type of delivery called a "monitored delivery" where they observe you and follow you after letting you take possession while they build a case against you. This is usually only done with large packages / deliveries, especially ones where they need to learn more about the trafficking network in an effort to take the whole network down.
Both are difficult to defend against.
Some interesting on-topic reading: https://www.reddit.com/r/DankNation/comments/43752z/info_on_controlled_deliveries/