After thinking about your request more, it is not a good idea to allow 1-pt quadrature for general 3-d solid elements. If the elements are distorted (your mesh seems regular) this would lead to errors as even the volume is no longer preserved.
Instead, the request will be tracked as an error by checking the value of "d(5)" in the quadr3d.f routine.
Also, when I forced 1-pt on the element the TANG command reported a singularity.