Possibly, but equally likely is that the “liar” tag will have stuck too
Not as much. It’s just the psychology of people who can’t or won’t fit any more in their heads. Every time the £2094 is mentioned, many people half-listening will go “that’s the figure Labour will put my tax up by” and possibly “oh, they’re denying it, but they would do that”.
It is a sort of Cummings-esque play – “I don’t give a shit about the number, just pick one that sounds bad and get it out there as often as possible”.
It is a measure of the disdain the Tories in particular hold the average voter in.