its not just the beer that does that. there are other options. however they are one of the most common. that other feature you mentioned is the main reason why i bought mine before. i planned to make the car for drag/grip applications. for drag i need an anti-lag system that will spool my turbos while im about to launch. what it does is its attached to your ebrake. while your ebrake is enganged it will switch to mode 2. beer has three knobs. first is for setting rpms in mode 1/normal driving, second is for setting rpms in mode2/ ebrake engaged, third is for setting how much fuel it dumps. only bad thing about it is that after using it for a long period of time. it will eventually create excess carbon deposits in your engine. more than you would normally get without the revlimiter hooked up.
i can get one if you want. pm me and we can talk about it. stock one isnt safe at high rpms isnt because it cuts fuel. ever tried redlining a car when your near empty? bee*r is safer because instead of cutting fuel it cuts the spark so it just dumps fuel. much safer for high rpms but not that good for your engine over time.