The idea would be to move events and process api definitions to jbpm-flow-api as low level api to access the engine.
org.kie.api.runtime.process
org.kie.api.definition.process
org.kie.api.event.process
org.kie.api.event.usertask

also move the internal from kogito-api processes to this new package. to contain the low level api in there.

Regarding missing things that was used by jBPM but also drools

org.kie.api.internal.assembler
org.kie.api.marshalling
org.kie.api.persistence.api
og.kie.api.time
org.kie.api.event.kiescanner
org.kie.api.event.kiebase