Yeah i wouldn't spray it on anything electronic i've just always sprayed it on fasteners, block,etc anything the salt air gets too. I'm sure i've hit modules,etc too just being quick (I used spray the heck out of the jet ski with it and it stayed new looking) can't say i've ever had an electrical problem on anything, but probably best to avoid those.
It's in a spray can so i'm sure it's a solvent that evaporates and whatever the waxy film is. Around here in florida you pretty much use that or corrosionX, i've never used that one.
That said i've seen outboards just washed down look good too. Its just one of those things i bought a long time ago for a jet ski (i think yamaha had something similar probably rebadged at the time they recommended) and just kept using it to inboards then to outboards because i never really saw much corrosion anywhere.
I just kind of trust it works, my last outboard was on a pontoon kept on a lift and after 10 years the motor looked new inside except for the tattletale area where there's constant saltwater contact and you really can't rinse with the cover on or don't when you're in a hurry...and I never rinsed under the cover of that one.
not sure much holds up to constant salt water exposure as it will wash pretty much anything off, wd40 I can't imagine lasts very long I notice bow rails rust in a week with that on but then again that gets a lot of rain , salt spray which would wash it off eventually, under a cover it may last just as long who knows!