Yeah, but, I don't see how that really changes anything.
On a smaller instance (or one that's defederated from others ... in either direction), that might very well completely shift focuses.
For the Fediverse specific community, if you want one with the most chance of getting to the developers, use the instance that they're on, otherwise, I'd think to just let the cultures develop and diverge naturally as they're likely to.
You can enable an email address for it and then can email EPUBs to it, so can use it without paying more to Amazon.