They are already serving access denied replies, so I assume they can identify the browsers via user agent or similar? If so, returning a bogus file that blocks

They are already serving access denied replies, so I assume they can identify the browsers via user agent or similar? If so, returning a bogus file that blocks everything and adding a comment in that list asking the developers to use caching or mirroring the file should be fine. I wonder if those browsers honor the list when fetching the update though. Would be awesome if you could just add easylist and lock out further requests right on the device.