While there are workarounds with Busy, I would like to offer a different point of view.

As someone who was bullied a lot in school, having teleports interrupted multiple times in a row give very, VERY uncomfortable flashbacks to feelings of being unable to escape someone who wishes you harm.

A single interrupt just to be teasing? I'll shrug it off. Having someone effectively lock me down (I didn't KNOW Busy would stop trades and let me teleport in peace) made me log out of the game and not come back for three hours thanks to a panic attack.

If you weren't bullied in school, or if this doesn't affect you, good for you. For others it brings up very bad memories, so please keep that in mind. Having trade not stop a teleport does nothing to make your experience in the game any worse - unless you're the kind of person who only has fun by taking away fun from others, I guess.