A brief update on how the artifacts of mbeddr, mbeddr.platform, and IETS3 have been changed (for the people that have to deal with older MPS models made using one of the mentioned extension packages): up until MPS 2019.2, it was possible to download all artifacts from build.mbeddr.com. Today, I was trying to do this as well, but it seems all the artifacts have been wiped for mentioned MPS versions (maybe some space needed to be made free on build.mbeddr.com, or maybe some internal build process changed). Now you have to actually get the label of a version that has successfully built from build.mbeddr.com (e.g. 2019.3.22698.f4cbbf7 of the mbeddr platform or 2020.1.4698.e240d62 of IETS3.opensource, the latter leading to https://projects.itemis.de/nexus/content/repositories/mbeddr/org/iets3/opensource/2020.1.4698.e240d62/opensource-2020.1.4698.e240d62.zip) and then get the corresponding artifacts from https://projects.itemis.de/nexus/content/repositories/mbeddr. Especially for IETS3 (KernelF), this is really needed.
Note: since MPS 2020.2, it is possible to simply get release artifacts from github (e.g. https://github.com/IETS3/iets3.opensource/releases/download/nightly-2020.2.4726.e49ca16/org.iets3.opensource-with-dependencies-2020.2.4726.e49ca16.zip). And these artifacts even include the dependencies (such as mbeddr platform, which is needed by KernelF/IETS3).