Demon Carburetor issue

It is possible to mask a lean transition with more pump or nozzle. That should really be avoided if possible, because your steady cruise can still be lean. That can also raise your operating temp some if it was getting toward the extreme side. Reading a fresh set of plugs after some miles would show whether that's a issue.

Totally agree.

Big cams generally require a richer fuel mixture because their not efficient at low speeds. I believe your jetting it way down like you did was counter productive and the extra pump shot is just a Band-Aid fix. Generally out of the box jetting is pretty close. You rarely have to go more than 2 jet sizes one way or the other. Why did you jet it down so far?