Fact of the matter is that even if we assume that we don't know they flag packages that are checked with Tor, if they start to do so they will likely be able to intercept a ton of drug packages. So it is best to assume that checking a package with Tor flags it, and vendors and customers alike should avoid doing so. If a customer has something being sent right to their house, the only advantage they get from not checking tracking directly is increased plausible deniability. I am not sure if that is going to save the day, but I am sure checking tracking with Tor could ruin the day. Using Tor to access third party tracking sites, and hoping they don't flag packages / pass on that you checked with Tor, is a superior option but may very well fail in itself. Using open WiFi from random locations is a superior option as well, but even this can be flagged (hmm this address has packages going to it and the person checking tracking seems to use a different IP address every time!). Obviously if you are getting things sent to a fake ID box or a place not tied to your identity, checking tracking without Tor or similar anonymity completely ruins the point of doing so. It is a complicated matter, and one that requires a great deal of attention to be paid to it, because tracking is certainly an attack vector that could lead to a large amount of interceptions if we are careless with how we utilize it. On the other hand, tracking can help us prevent being busted in the event of an interception as well (provided they still leave artifacts of interception on tracking, I know for a fact that they have in the past).