Can confirm the ML140 works fine in the C1.
Fan curves all still work, obviously its slightly higher that the standard fan speeds and this reflects in the curve giving slightly better cooling.
On idle (and fan at lowest speed, 428 rpm) my temps are:
9700k
CPU coolant 28.9
CPU Package 31
RTX 2080
GPUcoolant 32.9
GPU 36
Hope this helps
edit: Ambient temp was 18.7!