@oleg - What I am trying to embed is a custom front-end to a MySQL database. I previously put in a substantial effort trying to do everything with Coda, but I realized that the database features of Coda seem to have a realistic upper end somewhere in the single-thousands of records. My database is considerably larger than that, so I decided to use MySQL.
I certainly could do the whole front end at this point with a typical HTML/CSS/Javascript website - but Coda has really nice potential as the primary user interface. So I was hoping to combine the best of both worlds and embed my database front end inside Coda.
It’s so close to being a win-win design - especially given your new option to create a public-facing document inside an iFrame. But “Click to Enable” at most works inside an organization; it is not very professional appearing to share with a client and certainly would not work for a public-facing document.