While we have been working with this state of the code on MPS 3.0 for weeks now and consider it stable, there may still be a few bugs as a consequence of the migration (hence the EAP: Early Access Preview). Also, we have not updated the user guide in a while, so it may not be correct in every detail.
We have scheduled time for working on the user guide later this year, and we are also working on more convenient versions of getting mbeddr. Among them an mbeddr-specific MPS build that contains all mbeddr-relevant plugins (and only those!) as well as a one-click installer (at least for Windows) that also installs all the necessary tools (cygwin, git, verifiers, etc.).