“Creating new knowledge” is not thought of pushing past 80 if that’s the the limit placed by prerequisites. That has the error of creating the same knowledge used before. I think it’s less likely you’ll create new knowledge. You know a good amount of CF, so some stuff might actually be new.
The last clause of the sentence:
“but” shows a contrast between two ideas. I think that’s the contrast between needing to be at a 100 to create new knowledge and being able to create knowledge near the max. You don’t need to be at 100 to create new knowledge.
Getting to the maximum seems that it’ll take a lot of time. If you try doing that before creating new knowledge, you might not come up with anything ever.
“that” in the quote above is not “be thought” because that runs into in the error of why are you thinking that when getting close the maximum? What is your goal there?
How near do you have to be to start creating new knowledge? That would really help humanity if you start creating new knowledge. Maybe, it won’t help now but in the future.