Meanwhile, even newer versions of OMEMO (Version 0.4.0 and Version 0.7.0) are still considered experimental and not recommended, even though these are from 2020! XEP-0384: OMEMO Encryption
WARNING: This Standards-Track document is Experimental. Publication as an XMPP Extension Protocol does not imply approval of this proposal by the XMPP Standards Foundation. Implementation of the protocol described herein is encouraged in exploratory implementations, but production systems are advised to carefully consider whether it is appropriate to deploy implementations of this protocol before it advances to a status of Draft.
So, we’re either using outdated encryption or untested and incomplete encryption.
Version 0.7.0 introduced yet another protocol change: The HMAC-SHA-256 authentication tag is now truncated to 128 bits.
I thought it would be worth testing other XMPP clients with the latest versions of OMEMO and adding them to the wiki. But XMPP itself states that their use is not secure. However, using a 7-year-old version is considered normal. I didn’t use XMPP and wasn’t aware of this. I will note this in the documentation.