What's your definition of sustainable?

Sustainable up and until the debt ratio is reached?
This is one way of looking at it.

Another, which is the way I look at it:

Whether the increased debt burden from idle rewards, is closing the gap on the debt ratio.

Certainly, the debt ratio should be considered. I wouldn't be opposed to the interest rate gradually dropping as we start getting close. I don't think we are really there yet though. I don't think that the fact that it is currently closing the gap is reason enough. How big the gap currently is should also be considered. But I'm not really opposed to hitting the debt limit either...it's there to signal these things. If you think the debt limit is too high then I think that's a different argument. The other consideration for me would be how well HBD is holding to its peg. So far it seems to be doing well.

Personally, my goal is to have 50% hive power and 50% HBD (in value terms). Currently, I'm not there yet so I am accumulating HBD faster than HP. It won't stay that way though. Obviously, I can't speak for everyone's strategy. Obviously, if the interest rate changes, so does my strategy.

The problem with this view, is that the duration risk of HP is 13 weeks power down, and the opportunity cost of time is very significant in a highly volatile environment.

Isn't high risk, high (potential) reward basically the description of crypto in general? Either you believe in the future of hive or you don't. I don't think 20% for HBD is necessarily sustainable forever but I just don't really see a reason to change it now. It's also your choice whether you keep your hive powered up or not. If you don't want that opportunity cost, don't power up. I also wouldn't be opposed to lowering the power down time (but not too much).

Aside from this, I would also rather not leave things to the benevolence of the market. I think we should focus on what is rather than what could happen.

it's not the benevolence of the market, it's bet on the future of hive. The market is never "benevolent". It is self interested.

What we thought could happen, was a flywheel set off by the demand for HBD to also propel consistent demand into Hive. We got 7.5M HBD, but went from ~300M market cap for Hive to just over 100M - a pretty large discrepancy.

I would think there are a lot of things that affect these things besides the HBD interest rate. For as long as the HBD interest rate is high, there is the opportunity to attract more users and increase demand for hive as well. Once HBD interest rate drops, that opportunity goes away. Saying it hasn't worked yet isn't the same as saying it won't or can't work.

I do think HBD interest rate should drop before hitting the debt limit to avoid the haircut rule kicking in. But I think now is too soon and 12% is too big of a drop all at once.

But hey,