We published a full analysis of HF21 in two parts:

https://steempeak.com/hf21/@steembasicincome/sbi-in-an-hf21-world-part-1-50-50-rewards
https://busy.org/@steembasicincome/sbi-in-an-hf21-world-part-2-convergent-linear-and-downvote-pools