The main API issue with the v2017 changes was how exploded entities' IDs changed.
Perviously if you made a temporary group and got references to its edges/faces etc, then when you exploded the group you could reuse those references, if they were still valid.
With v2017 any in-group references are lost, all exploded entities get new IDs !
So all of the code using the old methods needs recasting so that it catches the IDs of the exploded entities, not there previous IDs.
Another workaround is to give the group's entities' custom attribute IDs and then re-collect them after the explosion...
This is possible: it's just a pain [PITA] to recode.
However, there are some subtle issues that are still unresolved.
In a few weeks I'll be at DevCamp... and then. hopefully, thomthom and others can help me track what's up with a few of my ExtrudeTools.
I have now trapped all of the issues which I can see, and I ensure that start/commit_operations are properly set... BUT in a few of the tools, although they complete their work perfectly, when the user subsequently does an UNDO it BugSplats ! That is after that extrude tool has successfully completed and the commit is properly recorded !!