The "max boost launch module" is also referred to as a "Jumper Valve". It's nothing new, in fact it's been around for quite some time. People have been making them for years from parts that are readily available via places like Graingers. Just recently some Buick suppliers (Kirbans, Rons Custom Auto, etc.) been offering these kits for sale pre-assembled.
It consists of a solenoid, switch, 2 t-fittings, and a few lengths of brake line. Basically what you do is create a bypass around your combination valve. Under normal use, when you hit your brake pedal the pressure is sent through the combination valve and then equally to front and rear wheels. When you hit your Jumper Valve switch, the solenoid opens which then lets your brake pressure go straight to the rear wheels. This is what allows you to hold the extra boost on the line.
I built my own (parts from Graingers) and it works VERY well. I had always had a problem holding boost on the line (never more than 5psi) and now I can hold 15psi +.
For more information on this, do a search on the Tech Section of this site. I think there was also an article a few months back in GM HighTech Performance.
Hope this helps,
-Banning.