When exporting my Wordpress blog, <iframe> tags disappeared (even though the <div>s and <p>s around them were generated.
This affected mostly Youtube, SlideShare and likewise embeded posts. Since I only had a few, I fixed them manually by copying from the old posts, but it might be desired to copy those tags.
Btw, this plugin is awesome - it was able to cope with > 14 years of bad HTML from my blog, and I deeply appreciate the effort put into it.
@chesterbr (or others) is this still the case? v2.0 and later have an updated export mechanism (Markdownify)
@benbalter unfortunately I don't have the old WordPress blog file, but Markdownify would (to the best of my knowledge) keep any "unknown" tags around, so I believe this could be closed if no one else bumps into the issue.
Thanks for looking at it!