Third party plugins typically don’t show up in RSS feeds.
Like if you had a plugin to add social media sharing buttons to the bottom of posts, they wouldn’t display in the RSS feed
A CTA should be an integral part of a blog article and therefore the HTML generated by the CTA plugin should flow through with the entire article in the RSS.
I previously used a plugin that generated a signature short code. I had my CTA in that signature short code and that carried over fine in the RSS.
Anyway you can implement something similar with your CTA plugin?
I think its possible but not currently on the roadmap.
You can request custom work here: http://www.inboundnow.com/premium-support/
