If you change over to a 209 ignition you might experience crud rings with your rifle... I also do not have crud rings to speak of with my Wolverine II LK-93 and #11 ignition. This winter I was shooting Pinnacle FFFg powder made by Goex. If you hate swabbing, I shot 12 consecutive rounds of 240 grain Thompson Center Mag Express XTP's and 90 grains of Pinnacle and never had to swab the barrel. The accuracy was real good. Although I did not try them at longer distances.

Also I think you hit your misfire problem right on the head. The change in temperatures is a killer to muzzleloaders. I had one in line fail last year. It had a 209 ignition. Of course the second cap did ignite it off. Also you have to make sure you recheck your load if a 209 fires but fails to ignite the charge. It will move them. The Wolverine on the other hand, I hunted one day in the worst kind of weather. It could not decide if it wanted to rain, sleet, or snow. I was doing a sneak through a cedar marsh. Never kicked up a deer but the rifle fired off perfect with the #11 cap at the end of the day being out in that mess..