Disclaimer: I do not understand all of the concepts that this question relies on, nor do i know what they're called and how to look it up.
At home, we're always told to use a spoon and not a knife in things like chummus and mayonnaise, so that it doesn't become milchig/fleishig. My understanding is that there's something special about a knife that can transfer kashrut status. (Maybe דוחקא דסכינא, Star-K's term.)
What about a knife without an actual blade? We have these spreaders that are basically knives without a blade. They're useful for cream cheese, butter, and the like. Since they are able to "cut" these soft things, and look like a knife, do the same halachot apply? (Of course, a spoon can also "cut" through soft spreads.)
Here's an example:
I suppose the question boils down to how sharp must a knife be to be able to change the status of things it touches.