I've had a similar arc, and spent some of my early time here mirroring posts between here, Medium, Substack, and my Write.as blog.
It wasn't a problem logistically (just lots of copying and pasting), but I increasingly felt like Medium and Substack weren't really communities, and that I was just pasting flyers to a lamppost downtown or something. Small communities are much more pleasant and worthwhile, even if they're surprisingly hard to find online.