For my Model X100D, I was able to get the "uncork" and on paper it shaved off like 0.1 second.
And it felt really the same, unlike Model S75D from 5.2 to 4.2 seconds.
I believe Model S100D is not much different from X100D. Personally, I wouldn't worry about 90D being "uncorked" as you will not likely feel the difference.