its not about starting at 100% and dropping to 0%

right now get a minimum + an amount

min + small = chem 43%
min + normal = nonchem 55%
min + wall = waller 61%+

instead it could be

max - small = chem 47%
max - normal = nonchem 35%
max - wall = waller 29%-

if you shifted the max down 4% or doubled the effect of chems you could even make chem stay the same if you wanted to

i wouldnt even hate the idea of modifying the chem number based on sdi to penalise getting sdi a little less