As the current fluent builder cannot (yet?) create all elements it would be very beneficial to have a way of creating elements yourself manually, but still leverage the auto-layout mechanism.

I did a quick hack to achieve it in this branch https://github.com/camunda/camunda-bpmn-model/commit/d38346380126113c1cf3cd3ae4cb737600ee03fa.

Otherwise you have to hack around a lot to do auto-layout for these elements (see e.g. https://github.com/flowing/flowing-trip-booking-saga/blob/master/src/main/java/io/flowing/trip/saga/camunda/SagaBuilder.java#L128).