Can you share this evidence that Centralnic owns 1api.net? I seem to fail to find such information.
Both appear to be under the roof of teaminternet.com but that doesn't imply Centralnic owns 1api.net.
Am now lost, what are all these domains for

See here only a few posts back:
If some good soul would compile a list of all the fake exch.net domains and list them one per line we could add them to the Domainsure Crypto Defender threat feed:
https://domainsure.com/rpz-threat-feeds/That gets pushed out to resolver services (like Quad9) which can dampen the reach of known phishing domains before they get taken down.