Ok I submitted my thesis.
In my thesis I'm using XEP-0223: Persistent Storage of Private Data via PubSub
But once I start to convert it to a standards draft I will switch to PEP nodes.
https://server.uwpx.org/nextcloud/index.php/s/LpBpwLJPiSidQiZ#pdfviewer
https://github.com/COM8/esp32-xmpp-iot