Excellent article. BPMN is great and I feel if often helps business/IT alignment.
However, diagram interchange remains a large problem. When you have to work with separate tools you’ll soon find that interchange is either a one-way-ticket or a concensus on a small subset of elements both support well enough. Especially when automation is one of your goals.
The MIWG doesn’t seem helpful to this cause, but who can you blame? It seems most vendors made up themselves what they understand by BPMN and don’t really care about spec compliance or other vendors.
Thanks for reading it 
It’s a good point about MIWG - although i believe interchange of BPMN is better off with MIWG it doesn’t solve all problems.
A lot of tools that implement BPMN tend to have a focus that they build towards. Camunda is focused on modeling for execution while Signavio is more interested in documentation so how we choose to implement the standard can sometimes rate to the persona that we’ve chosen to embrace.