Conservatively planning on 10% is a good idea. While the interest rate is high, it will only get you to your goal that much faster. Like you, I won't count on the interest rate to always be 20%. As we have seen recently, it is subject to change.

However, I wouldn't put too much thought into how sustainable 20% vs 10% is. If there is something fundamentally wrong that Hive can't maintain 20% with as few users as we are, then even 10% is a stretch. Reports from @dalz show how flat the debt ratio has been despite the 20% interest. If people were mortgaging their homes and selling off family members to get into HBD Savings, I might be convinced to worry about sustaining 20% interest with a constantly redlining debt ratio. Hive has protections in place to prevent collapse.

A more serious threat, in my opinion, is the lack of offramps for HBD. It's great to have the income. But if you can't withdraw it without converting to HIVE, it undermines the debt ratio.

The way you lay this out, it's like an annuity that pays out for the rest of your life. I have also given it thought. I'm still some years away from retirement. Each year that Hive celebrates another birthday, the long-term outlook improves. I can see myself contributing more to HBD savings to keep it growing, even in retirement. One of the advantages of whole life insurance, another form of annuity, is that the cash value increases annually. So, I would be well-served to continue to grow HBD Savings even while retired. This can be done out of pocket or by more blogging. At some point, I could see myself powering down a significant portion of my HP and converting to HBD. The goal is to grow interest income faster than the rate of inflation so that I don't spend my dotage in poverty.