I hope all is well! It looks like youtube videos currently cannot be embedded without iframes and, as you had mentioned, iframes are currently not supported in our html parameter. I did, however, relay feedback to the product team regarding this as an option. In html, we do support the
<video> tag, so it may be possible if the source file can somehow be hosted directly on the internet. If you end up testing this out and come across any issues, please contact us via chat or email@example.com.