By Julie J. -
While we do have the technology for auto-stroke detection, the Swim.com app is currently near the threshold of data available to third-party developers and there is not enough space to add the data for auto-stroke detection. We are always trying to find ways to nip and tuck data usage without hurting the quality of the features we currently have, but until Pebble increases the threshold it is likely we will not be able to add auto-stroke detection.
As a supplement, we have added a tool to the web browser edition of Swim.com that will allow you to edit stroke type and other discrepancies in your workout. Directions for how to use that tool are located here: http://support.swim.com/hc/en-us/articles/204340529-Editing-Workouts-Uploaded-With-a-Device