autofocus – Is there an mft adapter that is known to work well with sigmas or tamrons 150-600mm lenses

I own a panasonic gx9 camera and a 100-300mm lens. That gives nice reach, not that more reach could not be even nicer (for waterbirds etc)

Is there an adapter for micro four thirds that has good autofocus performance with any of the sigma or tamron zooms going up to 600mm? And does that combination have any other issues.

I am not concerned with weight or balance in this instance.