Anyone know what specifically triggers the home directory creation in
both the Bidir eDir and the regular eDir driver?

Docs are inconclusive.

The Bidir docs say to use the Set Destination Tempplate DN and the path
specified in the Home directory in the template will do the trick.
Interestingly, the regular eDir driver (checked 4.6, 4.5, 4.02, and 3.61
docs) do NOT mention this.

What I am seeing is that ndsHomeDirectory being set as an attribute is
triggering this process. But it is not working. But I have MakeHome
from JRB running at this client, so all I need to do is set the value,
and MakeHome will do the directory creation. (Yes there is still a
Netware server running an NLM in this tree.)

Are there any controls? Docs ignore the topic almost completely.

Currently IDM 4.02 but still of interest across versions.