ezmlm-idx/qmail do not currently support parsing of BATV encoded emails out of the box. Thus, neither do our lists.
When are you going to support the above
We have no finite timeline for fixing any of the issues above. It's simply not a priority, and we have fixed resources for dealing with other issues.
If we use ezmlm-idx/qmail in a standard configuration, then our service provider will support and manage the service. If we start adding random patches, then they won't - this makes our life painful. We do not like pain.