I have updated the AIP to include the additional compatibility discussions in this thread. Please take a look again.
Specifically (although by no means exclusively) it would be awesome if Michał you could have a look and see if it addresses more of the concerns and could be viable for you. Although the vote is non-binding, I still would like to be more confident I tried to address the real concerns from the community, which is the real problem when it comes to migration. Link to document for convenience https://cwiki.apache.org/confluence/x/2grOEg TP
