Correct! I actually have the replacing of placeholders down pat; the problem is more how do I insert placeholders into your plugin’s editor body. 
I’ve seen other posts that deal with this for the built-in rich text editor or text inputs (Add any text in any position within a text entry!) but was curious if someone has gotten it to work with the TinyMCE plugin.
That + this plugin would make creating rich-text content a breeze on Bubble.