You can take this part of the equation for Polkadot and change the expected weight percentage of the block as a variable. The current median for Kusama blocks is also 1.8%, so this can be tweaked anywhere from 1.8%-100% to find a value. This would mean going with the validator fee calculation, unless the average of the infrastructure calculation and the validator fee calculation is used. For Kusama using the median 1.8% results in .662 KSM (without locking opportunity cost discount) or .66 KSM (with discount). The average block weight is 13% (as there is quite a bit of variability over chains) which would result in 4.41 KSM without discount or 4.39 KSM with discount.
I should note, for this calculation I used the current average of Kusama validator rewards of .91 KSM per era/3.64 KSM a day rather than my estimate of 2 KSM in the original post (the rest of the numbers were confirmed besides this one - I didn’t have it until today).