It look like BFGs are being created for every stepback commit instead of the first one that failed. One example is BFG-393900 and BFG-394834. They were created from two consecutive commits on the same variant with the same failing task name and test name.
I have not checked other occurrences of stepback since Jira search in the build baron plugin has been timing out for me.
This is causing pain for build barons and it would be great if it could be prioritized.