What I'm looking for is the data. How many have failed and what kind of data is there.
As posted above, no compilation of doohickey failure data known.
Then, you ask, "What kind of data is there?"
Again, as mentioned above, anecdotal
data; often extracted from a sample size of ONE (1), or even smaller!
I think I failed to communicate the significance of the statement in my previous post, ". . . the OEM KLR owner dances upon a scaffold of PROBABILITY."
'Most everything has a probability of failure (even the SPACE SHUTTLE failed). A probability exists your doohickey and/or spring may fail. The magnitude of this probability remains unknown; a complementary probability exists the components will NOT fail. Thus, only you can decide whether to attempt managing the probabilities by upgrading components, or . . . rolling the dice Kawasaki has handed you.
In my view, the consequences of Generation 1 idler shaft lever failure remain significantly more severe than the relatively "fail-safe" consequences of Generation 2 loss of spring tension.
Basically, your call, whether to aftermarket anything on your bike or not. I would not proclaim failure to upgrade the doohickey (or even, absence of a Thermo-Bob) results in inevitable catastrophic engine damage, as some do. As men say, "YMMV!"