Every so often I run into a situation where I've created a full bleed design but when I go to set it up to print I realize that I forgot to include the bleed area past the trim line. Where this is especially annoying is when it is a photograph or piece of art that I don't really want to enlarge to account for the bleed.
A work around is copying and then reflecting the image on each edge and butting it up against the trim line. Also, you can generative fill the bleed area. Both of those tactics work, but they are annoying.
It would be awesome if there was a simple button to press where you said "create bleed" and you could set the size of the bleed you wanted and AI would just generate the bleed for you without any fuss. This would have to be in Photoshop.
Maybe this is just a me problem, lol, but we have the technology!!