Ah, ok!  That makes sense.  So then we should set it if it is not set, via
if (!is_set($this->typeAlias))
{
  $this->typeAlias = $this->type->type_alias;
}

In the batchset block.   I couldn't figure out how the code was working[ie running] without this being set.  It's possible it was set in the child class, if not set then it can be set using the type property.

Thanks!  When I get back this evening I'll update my copy and send a new pull request to Ellin[won't be till late, so if someone else can do it first that is fine with me]