We will leverage the existing 'tools' package and ensure it contains all of these special/additional extensions.  We will automatically generate version-specific instances of this package that contain appropriately 'converted' versions of the relevant extensions (e.g. pruning or converting target resources and allowed data types).  We will will adjust the tooling to automatically add an explicit dependency on this package for all new publications.   There may be some extensions where down-conversion is not possible for the tooling extension.  We'll figure out how to handle those if/when they manifest.