I'll add the suggestion to the todo-list but I'm afraid it will get a rather low priority.
There is no native way of writing exif data in java, so to add this I will have to do a lot of coding. There are some external libraries I can make use of instead, but some of them has quite poor performance. So I'm afraid adding exif data could have a bad performance impact.
In other words, this would take some time of investigating and testing...