Ah right, I'm not sure then... Maybe make another thread and we can discuss it?
I got it figured out

Even though I thought I had put in security access, maybe I'd closed that module and went back into it. It was merely a security access issue--I guess I'll update with a post on that thread.
As for HHA, the settings in VCDS are somewhat messed up. The actual adaptations seem to say that:
0 = normal
1 = early
2 = late
3 = late
But the popup dialog says that
0 = disabled
1 = normal
2 = early
3 = late
The latter group would make more sense to me and I did have it set to 1 (and was not working in reality). I've now set it to 0 and will then try 2 if 0 doesn't work, but I have a feeling neither will work.
Interestingly in the SSP 381 document it mentions
SSP 381 said:
In the ESP control unit has the same integrated
functions as in the Mk60 control unit on the Audi
A3, however these functions have been adapted to
the Audi TT. The hill hold assist (hha) and driver
steering recommendation (dsr) functions will be
implemented at a later date. The Audi A3 system
has been modified with regard to the operation of
the ESP Off key
It seems like this "later date" never really came? lol The document is from 2007 so if there's cars that are like 2013 and never rec'd these things, not sure they ever really followed up on that in the Mk2 years.
Also interesting DSR isn't implemented and later in the same document it mentions the steering rack is also modified from the A3 and does
not have DSR support; though granted this is a
very subtle feature and isn't really that important.