Ive had 2 different kinds of smoke pumps. The first one I had was just an electric pump with it s own battery, actuated by a micro switch from a servo on seperate channel. worked fine but when It wore out I installed tme simple smoke.

Much simpler to use. its an electric pump that just plugs into seperate channel. Dont need extra servo or switch.

As far as loading up on low rpm manuvers, Ive never had that problem. I mostly use it when Im doing low speed manuvers, that is probably why my plane gets so messy. There might be some extra smoke fluid running out not burning off. But if you think about it, the muffler is hot even at low rpm.

Sorry Im not full of knowledge, I just pump the stuff in and turn the switch on when I want smoke. How it works and why it works is not important to me, Just that it works.