I have a few answers:

1/ I saw the offers on all paid segments immediately after ticketing.
2/ The average cost to upfare each ticket is $1062, the average TOD is $1041 though it varies widely. On some tickets it's $800 over the upfare, on some it's $500 under.
3/ The underlying ticket price seems totally irrelevant. The TOD offer seems to be based on the number of J seats on the equipment, so the 319s are the highest cost every time.
4/ No offers on the award tickets.

The AUS-EGE nonstop is far more expensive (in Y or J) than connecting in DFW, but the TODs are cheaper. I assume this is because there are more J seats AUS-EGE on the CR7 than DFW-EGE on the 319. Yet another reason flying the 319 on that route makes no sense to me.