The boost bottle was used in dirt bikes, where a good low-end and midrange, along with neck-snapping response in those ranges, is much more important than high rpm usage. I don't think the latest ones use them though, cause the porting and carburetion used is much more advanced.

I dont know if conversion engines could benefit though. Probably not because most usage is in the mid-high to high rpm range. A pipe would be much better if a power boost is desired. But on the other hand, they could benefit because the carbs we are using (Walbro/Zama etc) are not really meant for a transition; they are meant for the engine to idle or be run at full throttle. So transition might benefit from using boost bottles.

Well, the only way is to "suck it and see"!