I’d rather have full oil pressure than have the added piston cooling of oil squirters even if they were easy to add, which they’re not. If you’re running water injection you can make it run cooler than when NA if you want to so why would you bother with oil squirters???
There are tons of failsafes out there, plus I’ve never seen a water injection setup fail. Some older kits had issues running 100% methanol, but that’s been resolved as well. I don’t use any warnings or failsafes on my own car because I’m totally confident in the meth kit. The meth pumps I sell are as reliable as a fuel pump…