There's several ways a DIY kit can be MUCH safer than a one size fits all kit.
Run a second pump with a switch setting a few psi. higher than your boost control setting or wastegate setting, over boosting will turn on the second pump and provide plenty of alky. protection, way more than any kit could do when you overshoot the 3 bar map control, then BOOM, or have maxxed out a single pump at a lower psi. than the map is reading, then BOOM when you go higher in boost.
Another scenario with the second pump would be a knock based turn on point, easily done with a simple counter, or tapping into a knock gauge.
And of course the savvy DIY'er can find a chip on the internet with progressive 0-5 volt control for PWM for about $1.50.
All you do is add a few simple components and a power mosfet or two and you have a progressive controller to use with your motorola transducer that has a nice 32psi. range for $20 and is more accurate than the GM Map for boost applications.
Simple staging of nozzles is easy and can be as good as or better than a progressive controller, but of course you do need to do some work and learn, rather than simply study the multi-page instructions and tuning information that some folks have trouble with for the "kits".
You can learn lots of things by trying, some folks learn the hard way however.
If you fear spritzing in alky. through a misting nozzle, may the Lord help you when you try to comprehend the alky. gooroos tuning methods for spark and timing and monitoring those pesky sensors and all to get the car running properly.
