Jerome, I have tinkered with a couple of fox forks and as far as I recall from the insides, there should be no reason you cannot take the fox reducer that takes their forks from 100mm-80mm and add it into an 80mm fork to reduce it to 60mm, and lower the A-C height, if you add it in the right place. I bet you could use a rockshox 20mm reducer in the right place too, if this doesn’t work for some reason. The suspension should not be “spikey” if you adjust your positive and negative air pressures correctly.
All you’re doing is adding a 20mm bumper under the top out stop, and then topping out where you would normally sit in a sagged mode at the end of the day, right?
Have fun tinkering and enjoy the geometry appropriate suspension on you aging wrists 😛
Rob