It's definitely something we've been looking into. Cancellation can be tricky because interrupting running code is either not possible or very complicated in Python. Many libraries choose not to allow cancellation of tasks once they’ve started running. Other times, they can perform “soft cancellation” in which the rest of the code moves on but the task continues running in the background. There’s a lot of variance in user expectations for cancellation and we’re still figuring out the best way to meet the majority of our user’s expectations while providing a robust and consistent cancellation method.