The thing is that the difficulty and relative score of the map should be recalculated at every note if we want a real estimate of the scurrent pp score
Like, after the first 50 notes at like 25 seconds, you can realculate what is the SR of those 50 notes and also the score (imagine like 40 MAX, 7 perfect and 3 great, taken to a maximum of 1,000,000 it would be like 950k for this 25 sec map)
When I fetched the project to try to implement mania, that's what I started to do at least (on time update, recalculate SR of current progression and current score, calculate pp from these)
"You" (i think) said that the estimate was accurate but after a few plays I figured out that it wasn't at all ^^ at the end it begins to be "quite" accurate but on a map really hard at the beginning and easy at the end it would be obvisouly inaccurate