Propagation usually stops at exchanges, payment processors, and other large services, because they pool funds from many unrelated users and treating every downstream customer as exposed would flood screening with false positives. Amount limits matter too: a dust transfer from a risky address should not make the recipient risky.
Direction matters as well. Paying a scam is usually a sign of a victim, not an operator, so exposure from victim payments is often treated as lower risk than exposure to the proceeds themselves.