Hello dlewis,
This was actually news to me.
After asking around the new HWD is a legacy HWD that are able to handle the old screen editor as well as the new. This to make the migration from old DP2x0 projects to the DM430 easier. There might be other differences as well.
The lack of information in the documentation is reported, and I understand that this will be updated as soon as possible.
Have a nice day.