On a side note, I recently saw something somewhere about how Substack is slowly working to fuck it's writers by taking more ownership of the subscribers list (so it can't be as easily moved elsewhere). Something to consider since you're considering building it up more. I really dont want a Substack account again but I will for you. Would appreciate an alternative or something on Nostr whenever possible.
This may be a thing at some point:
https://www.morningstar.com/news/pr-newswire/20240410da84128/former-truth-social-executive-to-launch-substack-alternative-letr