Dave, it sounds like you might have been more reluctant to adjust the needle setting than the comp, when it should really be the other way around. You really want to mess with the comp as little as necessary - too much fiddling (especially when running) and they can wear and become sloppy. (Unlike a needle valve.) Ideally you'll just find the right compression setting and then pretty much leave it alone. There'll be a bit of variation with different fuels and prop sizes, but not too much. Remember that a misfire could be due to too little compression, mixture too lean, or the engine just not being warmed up. Quite possibly your KMD could've just done with the needle open a turn or so for starting, a bit of a warm-up, and no need to touch the comp at all.

Sorry if this is telling you (or anyone else) to suck eggs!