Yes, yes I would.

At the moment, all data fits within the standard RSS fields. If I had to store the plaintext representation too, I would have to break the RSS spec and I can’t see the point of the extra engineering to do all this when appends are "good enough" for most purposes. The posts that matter the most when it comes to "correctness" are usually the OP, in which case, if you make a major mistake, just delete the thread and re-post.