I trend in PSE a lot, and frequently ask for a large time range of high resolution data on accident, because I specified it in my previous query. When this happens, I have to wait for the query to finish (could take minutes), or kill PSE. Others have suggested starting with a default range every time you trend, but I find keeping the previous time range useful. Instead, when I make this mistake, it would be nice to at least cancel the query. After or while hitting the cancel button, it would be nice to have a more intuitive way to edit the time range. I usually have to find a static attribute, trend it, adjust the time range, close the trend, and trend the desired attribute again.
Currently there is no way to cancel the trend from displaying the high resolution data. Even if the cancel button is pressed the data events received so far are still sent to the trend.
A backlog item has been added to the AF UI to find a better way to address this issue.