A simple tapped screw with a seal will allow bleed from multiple points if need be.
But not sure why you would want something like that. The water inside the head may be at an uneven temp on that part of the head. If you have a hot spot you may just want to run tje heatwr line out of that area and back to the pump that will pull fresh water into the hot area.
You may need to machine the head with a small lip for the thermostat seal. Also two thermostats do not work. But you can use several small orifices and run and open system. Keeps fluid moving across all surfaces if done right but usally getting the water in the raditator cold enough is all that is needed. Unless this is a mid engine build up. Big alum rad and good pump should sort it out.