No disagreement, DPelletier--any conflict appears to me to be regarding definition of terms: Specifically, what does, "critical" mean, in the context of the Thermo-Bob installation?
Further, I said the Therm-Bob raised the NOMINAL coolant operating temperature. Since the stock thermostat opens at a temperature lower than the Thermo-Bob's, I think the modified cooling system would operate at a higher nominal temperature. I'd question the term, "minimum," because . . . unless the thermostat is open, seems like to me the coolant temperature remains below that of the thermostat thresholds. If "operating temperature" occurs only when the thermostat opens, then . . . minimum operating temperature might be more appropriate terminology. I think KLR650 engines operate for considerable time during their service lives with thermostats closed, but I have no supporting evidence of the concept and could be in abject error.
You make the correct (but to some, controversial) comment regarding the Thermo-Bob's lack of influence on maximum coolant temperatures: After the thermostats open, stock or Thermo-Bob, either engine configuration's coolant temperature is at the total mercy of water pump circulation and air flow.
"Cold shock" remains an interesting concept; I've wondered at the failure mechanism and the components affected from the phenomenon; same for "heat cycling," reduced by the Thermo-Bob's greater temperature stability than that of the stock system.
Then . . . some believe the absence of a Thermo-Bob causes cylinder bore distortion ("ovalization"), with consequent ring failure and excessive oil consumption.
I think the Thermo-Bob appears consistent with physicians' Hippocratic Oath, "First, do no harm." Critical? Each rider alone determines whether the modification is "critical," to himself.
DISCLAIMER: My riding partner, 95,000 miles on his '08, LOVES his Thermo-Bob!
Peripheral thought: Does the disappearance of the KLR from the market affect Thermo-Bob sales numbers? Will the Kawasaki successor (if any) to the KLR650 have a modern coolant bypass cooling system (as now offered by the aftermarket Thermo-Bob)?
“You better put down that gun. You got two ways to go, put it down or use it. Even if you tie me, you’re gonna be dead.” "John Russell" (Paul Newman), Hombre