It’s not clear what you’re referring to but I believe you’re asking if the content of custom thread fields can appear in thread RSS feeds.
I’d have to disagree that the thread field content is the most important part of a thread generally. It would require custom development or an add-on to change the behaviour here - I don’t think one exists already.
As a reminder, please use ticket support if you require a response from a staff member or a quicker response than you might get on the forum.