Moving Hunter's Mark without a Bonus Action

What if there were a new Ranger class feature that came online around level 5 that allowed you to move Hunter's Mark to a new target without using a Bonus action? Let's say something like this:

Rapid Targeting. If the target of your Hunter's Mark drops to 0 hit points before the spell ends, you can move the mark to a new creature without using a Bonus action. You can still only move the mark once per turn.

The intent would be to get the Hunter's Mark bonus action out of the way of things like the Dual Wielder bonus action or the bonus action required by a Beastmaster Ranger to control their companion. Both of these things can already be used with Hunter's Mark, but the combo takes some time to set up, and the setup can be undone in an instant if the target suddenly dies. The new feature would come online at about the time the Ranger starts to struggle compared to other martial classes, and also around the time when there is more competition for the bonus action from feats and subclass features.

Can't that just be a feature of the spell?  Would solve 1 out of 9 problems with it.  

Hunter's Mark, used in conjunction with even a small amount of cheese, can allow you to do anywhere from six to eight additional d6's of damage per turn for an hour. That the spell is allowing you to functionally re-cast it for free is actually crazy, so the "limitation" that you need to functionally re-cast it is a small price to pay in exchange for functionally re-casting it.

Personally, I think Hunter's Mark is already bordering on too powerful. If I had my way, it would not be movable to additional targets - but alas, I am not one of the Devs. As such, I would not support such a change.