THE FORK WORKS
First difficulty oscillation: BOTTOM 1, TOP 139
Second diff oscillation: BOTTOM 1.19, TOP 79
GOING DOWN
The system is very underdamped, but should still reach equilibrium before too long. If a couple of two-hour block times happen every day it is at least usable.
The 12% limit is too large... at least for increases. It allows a 60x retarget in only 36 blocks.
No. It chases the hashrape away. It never gets to 60x. Don't worry about that. It needs to be 12%.
If it's less the swings will be worse because the hashrape will last longer and the difficulty will be higher at the peak. If it's more they will also be worse, because it will allow the difficulty to jump TOO fast.