Idk, I think pushing to move the party left and working within the bounds of the party positions are kind of mutually exclusive, right?
Like as an example, if I thought we should all have pineapple on pizza, but the party position was to have mushrooms instead, I would need to vocalize that desire for pineapple somehow, right? I would at least say, "hey, I don't want mushrooms on my pizza. Could we do pineapple instead?".
I don't think quietly accepting the mushrooms is at all compatible with pushing for pineapple.