Can you send me the bindat to look at? Maybe it's just a problem of the bindat not getting built right, so maybe we could fix it at a binary level...
Well ... I did some research here and the problem that I have created STATIC tags. As I understand all *.HIE files stored a static information. These TAGS are similar UNITTYPES and, as we know it, the developers have blocked this.
You know, If I remember correctly the Feature tag editor was broken when runic update GUTS so we couldn't create new Static Unittypes.
This is not entirely true, we CAN create a static tag, but it does not work in the game.

This means we need dynamic tags!

And I have the solution!
What I've done?
1. Create a new folder FEATURETAGS in MEDIA.
2. Then create all the necessary DAT-files with your tags (these files are similar to dynamic UNITTYPES):
EC_DEADS.DAT
[EC_DEADS]
<STRING>NAME:EC_DEADS
[/EC_DEADS]EC_DEAD_P01.DAT
[EC_DEAD_P01]
<STRING>NAME:EC_DEAD_P01
<STRING>CHILD:EC_DEADS
[/EC_DEAD_P01]...
EC_DEAD_P10.DAT
[EC_DEAD_P10]
<STRING>NAME:EC_DEAD_P10
<STRING>CHILD:EC_DEADS
[/EC_DEAD_P10]For this you can use the UNITTYPES Editor:

Then, when you create these "fake" unittypes - cut them out from UNITTYPES folder and paste in the FEATURETAGS folder.
These tags work perfectly in GUTS and in the game. This is Victory!

Hooray, I have made the dynamic tags!
In the game:

upd: Oh, it's my first screenshot with my pre-pre-pre-alfa start area!