Maybe there's a little misunderstanding?!

This dust-rule we're dealing with here applies to combined rewards, so two 1-cent-votes would still make sure there's enough rewards to not be dust and it will be paid out. This is exactly where the bunny comes in, it will upvote just as much on top of the existing rewards as what's needed to bring them over the dust-limit (with a generous safety margin) at least 12 hours before payout.

During the last 12 hours before payout, voting efficiency decreases, so anything that's not fluffed up by the bunny at that point, that means the bunny didn't get to it.

But, there's actually a dust-vote policy as well... before HF20 the blockchain completely rejected votes if they were too small. Since HF20 this has been changed by reducing all votes by 50million rshares (that's maybe 1.5SP?!), smaller votes will be treated as actual dust-voytes with zero rshares. This has nothing to do with the bunny's purpose, though.