^^^ In response to the previous two ideas, there seems to always be a way to make something work in this program, it's very versatile. But personally, I would rather something like this be made an option in the image editor rather than using events to get the result. You should be able to highlight all of your frames in the image editor and then select what command you want to apply to those frames, click the command, and then done.
Importing images in a batch in Construct is as simple as clicking 'import frames' and then highlighting all the frames you want, then clicking 'open'. It should be just that simple to batch export, resize, and crop, as well. We're already 50% of the way there since the importing function already allows for batch commands.