I'm definitely interested. Just got my MX11800 in the mail yesterday!
Will there still be a tactile bump? I know the blacks are linear, is this the mech or the spring?? I'd still like the tactile bump, but I'd like the keys to be a little harder to depress. If that's the case then count me in 
Kind of backwards from what I was originally talking about, but I am open to do that as well since I have so many extra black switches.
If you want to keep the tactility, but just increase resistance, then I would just swap your spring for the spring from one of my black switches. Then I would take your lighter spring and make the "ghetto reds" for myself.
They call the browns with the heavier (mx black) spring "ghetto clears" but really the tactile bump isn't the same as the clears, but he force will be similar.
Shoot me a pm if you still are interested.