Of course with a uwa, it is easy to manually focus, your dof is nearly everything you see in the frame. I am pretty sure discussions are around everyday walk-about lenses.
It's quite easy to MF large aperture lenses in the Sony, at least for me. In fact, for swimming, I do better with MF due to the fact the AF confusion when a swimmer is under water. With peaking fine tuned to your lens of choice, you can quickly MF without 10x magnification.