someone help me to math out elusive

so i have elevated elusive on my boots already, and just out of curiosity i checked the new runegrafts and saw the "runegraft of the agile" which makes elusive gain effect the first 2 seconds instead of remove it.

im not that good at math so how much would i gain from this runegraft with elevated elusive on boots?
also maybe calculate the gain from going for the oshabi ascendancy "the vivid cat"

https://pobb.in/c_22-SE-iOSs

thats my pob if it matters (currently tailwind and wild savagery are my sources for action speed)

Without any modifiers, Elusive always starts at 100 % effect when it is gained. From that point, the effect decays by 20 % per second until it reaches 0 %.

Your boots provide a 20 % chance to gain Elusive on critical strike. This only affects the trigger chance, the effect itself still begins at 100 %.

My understanding is that, with the Runegraft, during the first two seconds, Elusive does not decay. Instead, its effect increases by 20 % per second. As a result, the effect rises from 100 % to 140 %. After those two seconds, the normal decay resumes and the effect then decreases by 20 % per second until it reaches 0 %.

In practice, this means that with the Runegraft the effect curve is 100 % to 140 % to 0 %, whereas without it the curve would simply be 100 % to 0 % over time.

I think with that curve, which everything above sounds correct, just haven't gone through and looked myself, you would have average elusive of:

(((100+140)/2)persecond*2second + ((140+0)/2)persecond*7seconds))/9seconds= 81 elusive (rounded down). As apposed to 50%.

Increased elusive effect if you had any sources, would modify those numbers but making the starting value higher. There might be a way to interrupt it and reapply it quickly as well, so you are staying in the high part of the curve more often and increase that value further. Not sure if that tech is available currently, but I think it has at times been possible.