I was just thinking about this, and I wonder if it does work, but for a completely different reason than it's supposed to.

My recent adventure with increasing the exhaust timing on a crappy engine has given me reason to consider, what if the RB Innovations "supercharger" generates just enough extra pressure in the intake to have a similar effect as mildly increasing the intake and exhaust timing? As a general rule, our little nitro engines don't get anywhere near their metallurgical limits (except for the occasional defective part, anyway), because nobody wants to get a reputation for making engines that explode during the A-main. While our little nitro engines don't have RPM limiters like full-size engines have, they are still effectively RPM-limited by their ability to suck in fresh air and fuel and push out exhaust. Since our little engines are essentially suffocating at high RPM, slightly better intake airflow would produce slightly higher pressure in the bottom of the crankcase at high RPM, enabling the transfer ports to scavenge the combustion chamber slightly more thoroughly. (I'm repeating the word "slightly" over and over on purpose.) So, even though there's no way the "supercharger" could actually pack more air and fuel into the combustion chamber, and even though any extra fuel that made it into the engine would be wasted straight out the exhaust, the "supercharger" might make a crappy engine run a little less crappy.

If it works the way I suggested, it would still be a ham-fisted alternative to actually learning how a valveless 2-stroke engine works and making adjustments correctly, but it would at least be more than a placebo effect.