As you point out BBR has some features that are interesting and well-designed, though there are also some issues with them.
I admire this idea [blockchain as scratchpad] as a short-time way to help insure CPU-only. I need to study it more to see if I can find any flaw.
It certainly is not CPU-only even short term as there have been private GPU miners with a significant advantage since shortly after launch (and public ones recently).
We have studied every BBR feature. I'm not familiar with Infinium-8 yet. As always it is hard to keep up with the flood of shitcoins. I'm pretty sure the mining reward as a function of difficulty idea comes from some bitcoin clones though. It is not new.