Hmm... seems that another question comes to mind...
Looking thru the various archived copies of the WIL SDK that accumulated on my dev system over time, as well as various extenders I've written and may or may not have made any updates to over a span of years, it looks like there's a range of Extender Interface Versions ranging from 2 thru 5, and Feature Levels going back to what might be a deprecated 1001 level, as well as levels 1002 thru 1009.
Does the current release of WinBatch drop support for any of those interface versions and/or feature levels, or does it happily load all extenders with interface version >= 2 and feature level >= 1002?
Also, I noticed that some of the feature level increments had to do with changes in behavior but not necessarily changes in existing data structures, etc..., and so they might not be obvious. Is there a feature level > 1009, or is that the current high value for it?