How to create Association-Flow in Fluent BPMN API?

Hello,
Please Help me, I have a big problem with the process of generating the diagram (Tag </ bpmndi: BPMNDiagram>)

I developed a program with Camunda API on Eclipse (Java), at the end, the rendering engine of the BPMN2 modeler plugin is very very heavy (1 hour to generate a BPMNDiagram of two elements but in addition sometimes it freezes).

I decided to switch to Fluent API (because it supports the generation of the BPMNDiagram) but I faced a big problem: Fluent API does not support the creation of AssociationFlow (not sequentiel flow) and all my work on Eclipse falls into the water :frowning:

Is there a way to create an AssociationFlow on Fluent ((or a way to represent a flow between a subpress and its nested process (this is the main reason why I use the associationflow because it is not possible with sequentialFlow)

Is there a way to load a BPMN file generated with Camunda (not containing BPMNDiagram) with Fluent, then, ask Fluent to generate me BPMNDiagram.

Thanks All.