The centrifugal force stress at the hub (root) of a blade is thousands of times the weight of the blade. Easily there's tens to hundreds of tons of force "trying" to pull the blade apart and this not so little nick, makes that much more likely to succeed.

If the drone is clearly outside the radius of the main rotor, you'd set down. What if it's above the rotor coming toward you? Probably set down and hope it doesn't get sucked in? What if it's below the main rotor coming toward you? You may not want to set down unless you know (?) the downwash is something the drone can't put up with, but how much time are you going to have to decide whether to risk striking it with a rotor vs throttle up delay and ascending away from the drone?

I think the behavior of various sized drones in proximity to helicopters is going to become a necessary training item. There will be planned and unplanned close proximity of s/mUAS and the worst enemy is going to be having never thought of or discussed these operational what ifs.