Ha! Glad my modding had some value!
Surprisingly, I've never had a problem with it, even though it's just "crammed" in there. Just hate cutting into harnesses if I can help it.
Since I'm mostly city driving, I find the switch the most useful when my battery is nearly dead and I don't want to allow it to get to the point where it force regens, so I just go IMA-less with it until I can get to the charger. (I'm one of those "bad examples" where I grid charge almost exclusively when the battery is near dead. My theory is: Your car is gonna charge the battery using fuel, so why not use cheaper electricity from your home instead? Just time it and/or monitor voltage carefully.)