Howdy!

The super-useful multisite feature where you import settings from another site is populated with this:

$public_sites     = get_sites( [ ‘public’ => true ] );

Unfortunately, this defaults to 100 sites. Consider adding ‘number’ = >0 to get all sites.

That 100 default is there as a sane default for VERY large networks. You could consider using wp_is_large_network first to make sure it’s not a totally insane amount, but not sure what makes sense to do in that case (or if you care).

I’ll let you know how we plan to use this feature, in case it’s helpful how you think about things:
We plan on just creating a site on each network that’s only purpose is to be a “Simply Static Settings Site”, and configure our preferred settings there. Before we generate an export for any site, we’d import the settings from this site.

Cheers!