Glad to see you got your Cub back up to power. The only thing I have to add regards the smoke you are seeing. From what I could see in your video, the smoke only seems to occur on cranking and when the engine first takes up a load (climbing a hill, engaging the mower, etc.), and then clears up. From what I understand, that's perfectly normal - except that it is generally a bit darker, more towards black (ill have to say the white smoke had me concerned at first, but it seemed to clear up in no time) - and all internal combustion engines do this. Maybe the white color has something to do with the additive you're using?
Anyway, it's great that you are up and running.