Thanks, Lee. I've been using the designer for a while now, but I guess it was perhaps too obvious a step to delete the caption from the XML that it didn't even occur to me. (I suppose even if it had occurred, I would have figured the designer would just pop that right back in there.)
Of course, I just fired up my newly-installed Designer 7.1 and this isn't even an issue any longer! Indeed, the additional options that had been spoken of are present, and the caption handling is more like my sensibilities say it should be.