If possible, it would be great if there was a ‘Success’ output port on Writers (I don’t mean FeatureWriters), so that you can use that to initiate subsequent processes. I often need to control the order that processes need to run between different datasets.
I tried using FeatureWriters and FeatureReaders, using the ‘Summary’ and ‘Initiator’ ports, which works fine in Workbench, but there’s apparently a bug in Flow when outputting to an ArcGISFeatureService.

