HSK rating algorithm, that also uses a more difficult wordlist? Is this list primarily HSK5-6 or do you mean parts of the list I PM'd you? If the latter I'm curious as to how you're going to organize them. Personally I have always thought that the HSK difficulty grading is a big mess. Like why is 既然 HSK4, but 帐篷 or like 指甲 is HSK6？ Maybe it's because I started reading books like this before I even started reviewing the HSK books published by BLCUP(?).Your feedback is welcomed. Next, I'd like to improve the HSK rating algorithm.
Maybe a bit random, but like 8-9 years ago I had to review and improve my math skills before I could enrol into an Engineering degree so I took the math courses over at Khanacademy. Back then, they use to have this knowledge map (click here for image) that worked as a progression map. I thought it was great. IF only there was a Chinese language app/website that did something similar (there probably is, but I am willing to bet it goes till like HSK3-4) that guides you through the language from nothing to native.
The issue with the current HSK system is that you progress rather quickly through HSK1-3, but then it literally slows down exponentially. As such most people overestimate their skills in Chinese and underestimate the amount of effort they have to put in to achieve even a smidgen of fluency.
P.S. 昏昏欲睡 isn't part of the current HSK, let alone the newly proposed one. Also, it's like 600+ in the frequency list. How do you rate 昏昏欲睡 as HSK5 when, IIRC, HSK5 itself only has a single idiom（讨价还价).