Every blessed time I do it the 'right' way, I get a heart palpitation courtesy of a backfire. Rarely to never when I idle them down. 25 hp courage, 26 magnum, and 26 elite in the mix.
I'm unfamiliar with these engines. I know there are differences in the shutdown procedure between some. The 26 Command, for example, does call for a low idle shutdown. I think the input need to remain with the 25 hp Command vs other models, for accurate info.
My experience with my only Magnum, and all Commands I've had is just the opposite. My KT's have been mixed. I could get rich betting that each of my CH25's will backfire if idled down before I flip the key off. I leave my RPM right at 2250 on the tach, and have never once had a backfire since changing my method. Took some getting used to...I just can't bring myself to shutting down from a higher speed than that, and haven't had to try.
I think the Kohler tech's would provide plenty of backup to the factory's recommendation, but each engine will act differently. There are quite a few guys out there with this very problem, who either fault the engine, or simply change their tune about the shutdown process and go on with life. If you have the solenoid, and it backfires at the recommended RPM shutdown, then by all means, do what you need to, to prevent it. But obviously, that isn't the case here.
It's amazing how folks cannot change their school of thought, regardless of the consequences and fact behind it. I'm a terrible example...I've been running my engines by the book for only about 2 years now, and while it is clearly correct, I still cringe every single time. Every time. I always feel like Grandpa is shaking his head, and I know for a fact that my old man just would NOT leave that idle up no matter what. But, Kohler built them, and Kohler says to leave the idle up, so I do, and I haven't so much as had a hiccup in 2000hrs of combined use on this model engine.