You don't know that until you paste, which might be a while after the copy and you also don't have the source available anymore in case it shows up weird, or yo

You don't know that until you paste, which might be a while after the copy and you also don't have the source available anymore in case it shows up weird, or you don't remember exactly what it was, or have it to compare to. This sounds quite cumbersome even for the techie. The basic text representation isn't enough. Maybe the text representation is correct but the html one embeds some javascript? How are you going to render that?