Wow this post came at the right time. I have been thinking about "taking profits" in a sustainable manner to protect myself from situations like the LUNA saga. The 90/10 rule seems interesting so thanks for sharing!
So far my initial thought is leave Hive as it is, but to take profits from the 20% interest from my HBD. Since my post rewards are 50% Hive/50% HBD, over time HBD will grow so the 20% interest will continue to grow as well.
It's pretty difficult to say in advance what will survive and what will not. With my 90/10 approach I always manage to pull some money out of things without hurting the project and still to build where it matters most to mee.
For me HBD is one of my main goals so I try to increase my stake also because I want to earn more of these interests :-)