Quote Originally Posted by desbromilow View Post
for me the original design of Marv's tool needs the slot to break out at the end of the handle so the long arm can also fit in the handle, and the short arm used as intended. The handle would then give a shorter handle 180 degrees offset for tight work, and for some size keys add a measure of comfort when turning.
Look carefully at the first picture in my original post. The slot extends to the end of the handle as you wish. The plastic retainer conceals that fact in the other pictures but it's still there.

That said, I've never had occasion to use the handle in the way you describe. If the job requires that much torque I have several ratchet wrenches that can directly accept a 1/4" hex Allen tip. Much more comfortable than trying to put huge torque on the short end and the ratcheting ensures one can obtain a good wrenching position.