I asked Vaillant when my system would migrate to myVaillant. They said:
The sensoAPP and 700 apps are in the process of being upgraded to the myVAILLANT app on a new server.
The migration to the myVAILLANT app currently underway in batches and will be phased in by invitation only.
The app migration should be complete by early 2024, basic system setups first and complex systems (including ambiSENSE and 700 systems from late January to March 24).
Is it possible to connect my vaillant arotherm plus heat pump over eebus (vr921) with my home assistant?
I want that the heat pump works at daytime without cycling.
You can use the “myVaillant” integration.
Has anybody asked Vaillant whether they wrote any eebus code? I assume they didn’t find somebody who wanted to write Python eebus modules … at least I can’t find any on PyPI.
The best bet right now seems to be to use EVCC to talk to eebus …?
Vraag, Wij hebben thuis een Vaillant arotherm 75/5 warmtepomp. Ook hebben we 13 zonnepanelen .
Nu als de warmtepomp aangaat vraagt hij veel meer wat dan wat me zonnepanelen leveren. Nu wil ik eigenlijk dat de warmtepomp het aantal wat wat hij vraagt aanpast aan wat er via de panelen geleverd wordt. Heeft iemand een tip welk kastje ik hiervoor kan aanschaffen zodat me omvormer en warmtepomp met elkaar kunnen communiceren?
Well, I found this:
https://juser.fz-juelich.de/record/1025415
I have no idea whatsoever why somebody who writes a master thesis on a Python EEBus module would do so at an institute that’s dedicated to the functional structure of the human brain, but maybe he wrote it while he was inside a fMRI monitor and they watched which parts of his brain he was using for this? 
Seriously: I asked them and discovered that this work was in fact financed by Vaillant. Unfortunately the paper doesn’t seem to be available to the general public and I didn’t get a reply when I asked them about the availability of this code.
Maybe somebody else has better luck and/or knows somebody who works at Vaillant.