“what if we could then dynamically Niche so instead it's like they are getting a email that I send about the course and then if they're a Creator maybe I put the quote from Dickey push of ship 30 because he's a Creator and if they are a consultant maybe I put the quote from... they've used their clients to like make to basically they've taken what I've taught them and built a really good little personal freelancing or agency business”

Dynamically niche by swapping testimonials, not pages

Niching always wins, but running "Mastering ConvertKit for SaaS" AND "...for Book Authors" AND "...for Consultants" is insane. Keep one product page/email and conditionally swap the testimonial, case study, or single benefit paragraph based on what the visitor told you. Cheapest form of dynamic niching, and it's why generic "works for everyone" copy converts worse than either targeted version.