BAM would be a nice and important feature for newly designed systems, however in our project we already have our own external statistics facility,
with help of v5.4 NodeInstanceLog and other domain-specific entities, that's why we don't need a different implementation of the similar feature for now.
Maybe our system will be able to use bam in the future releases though.
For deletion, I would like to delete those tables to prevent row sizes from growing, so I realized from your reply that I could leave OrganizationalEntity untouched.