I tried to have my REST service microflow set up in a way so that on concurrent execution, configure the REST service's microflow RESTServiceMF to run another microflow ConcurrentExecMF that is to return a response object that is to indicate that a concurrent execution is taking place. However, concurrent requests for the REST service would always result with empty responses, which I believe is because the microflow ConcurrentExecMF is technically not a microflow set up to be used for a REST Service. I've also tried serializing the response object within ConcurrentExecMF and returning the json response string and that still resulted in an empty response. I am aware that throwing a custom REST service exception within ConcurrentExecMF is an option but was wondering if there are other ways to handle concurrent execution on REST services.